Specifically substituted ladder type compounds for organic light emitting devices

ABSTRACT

Specifically substituted ladder type compounds of formula (I) wherein A is formula (II) a material for an organic electroluminescence device comprising at least one compound of formula (I), and an organic electroluminescence device which comprises one or more organic thin film layers including an emitting layer between a cathode and an anode, wherein at least one layer of the organic thin film layers comprises at least one compound of formula (I).

The present invention relates to specifically substituted ladder typecompounds and organic electroluminescence devices comprising the same.

EP 2 301 926 A1 relates to a halogen compound, a polycyclic compound,and an organic electroluminescence device using the same, in particular,to an organic electroluminescence device, which shows high luminousefficiency and has a long lifetime, and to a polycyclic compound forrealizing the same, and a halogen compound serving as an intermediatefor the polycyclic compound. However, 9-substituted bis-carbazolederivatives are not mentioned.

EP 2 301 921 A1 relates to a polycyclic compound and an organicelectroluminescence device using the polycyclic compound, in particular,an organic electroluminescence device, which shows high luminousefficiency and has a long lifetime. However, 9-substituted bis-carbazolederivatives are not mentioned.

WO 2011/137072 A1 relates to phosphorescent organic materials comprisinga bicarbazole with a dibenzo or azadibenzo substitution. However,polycyclic compounds having at least five condensed rings comprisingbiscarbazoles are not mentioned.

Notwithstanding these developments, there remains a need for organiclight emitting devices comprising new materials, especially host(=matrix) materials, charge transport materials, i.e. hole transportmaterials and electron transport materials, and/or charge/excitonblocker materials, i.e. electron/exciton blocker materials andhole/exciton blocker materials, to provide improved performance ofelectroluminescent devices.

Accordingly, it is an object of the present invention, with respect tothe aforementioned prior art, to provide further materials suitable foruse in organic electronic devices and further applications in organicelectronics. More particularly, it should be possible to provide chargetransport materials, i.e. hole transport materials and electrontransport materials, and/or charge/exciton blocker materials, i.e.electron/exciton blocker materials and hole/exciton blocker materials,and host (=matrix) materials for use in organic electronic devices. Thematerials should be suitable especially for organic electronic deviceswhich comprise at least one emitter, which is a phosphorescence emitterand/or a fluorescence emitter.

Furthermore, the materials should be suitable for providing organicelectronic devices which ensure good performance of the organicelectronic devices, especially good operative lifetimes and a low useand operating voltage of the organic electronic devices.

Said object is solved by a compound of formula (I)

wherein

A is

X_(A) and X_(B) each independently represent O or S;

r represents 1, 2 or 3; in the case that r is 2 or 3, X_(B) as well asAr₃ are the same or different in each occurrence, preferably r is 1;

Ar₁, Ar₂ and Ar₃ each independently represent a substituted orunsubstituted aromatic hydrocarbon group having a ring structure formedof 6 to 30 carbon atoms or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms, and which islinked to one aromatic hydrocarbon group of Ar₁, Ar₂ respectively Ar₃via a carbon-carbon bond;

L represents a single bond, a substituted or unsubstituted alkylenegroup having 1 to 20 carbon atoms, a substituted or unsubstitutedcycloalkylene group having a ring structure formed of 3 to 20 carbonatoms, a substituted divalent silyl group having 2 to 20 carbon atoms, asubstituted or unsubstituted divalent aromatic hydrocarbon group havinga ring structure formed of 6 to 30 carbon atoms or a substituted orunsubstituted divalent heterocyclic group having a ring structure formedof 5 to 30 atoms;

m is 1, 2 or 3; in the case that m is 2 or 3, L is the same or differentin each occurrence, preferably m is 1;

R¹⁷ is a substituted or unsubstituted aromatic hydrocarbon group having6 to 30 ring carbon atoms or a substituted or unsubstituted heterocyclicgroup having 5 to 30 ring atoms, an alkyl group having 1 to 20 carbonatoms, a substituted or unsubstituted cycloalkyl group having a ringformed of 3 to 20 carbon atoms, a substituted or unsubstituted aralkylgroup having 7 to 24 carbon atoms;

L₁ is a single bond, a substituted or unsubstituted alkylene grouphaving 1 to 30 carbon atoms, a substituted or unsubstitutedcycloalkylene group having a ring structure formed of 3 to 20 carbonatoms, a substituted divalent silyl group having 2 to 20 carbon atoms, asubstituted or unsubstituted divalent aromatic hydrocarbon group havinga ring structure formed of 6 to 30 carbon atoms, or a substituted orunsubstituted divalent heterocyclic group having a ring structure formedof 5 to 30 atoms;

n is 1, 2 or 3; in the case that n is 2 or 3, L₁ is the same ordifferent in each occurrence;

Ar₄, Ar₅, Ar₆ and Ar₇ each independently represent a substituted orunsubstituted aromatic hydrocarbon group having a ring structure formedof 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms;

wherein the dotted line is a bonding site.

The specific bis-carbazole substitution of the compounds according toformula (I) gives rise to materials, especially host, charge transportor charge blocking materials, that are highly suitable in organicelectronic devices, preferably in organic electronic devices that emitgreen or red light. Moreover, a balanced charge transport, i.e. holetransport or electron transport, preferably hole transport and/orcharge/exciton blocking, i.e. electron/exciton blocking or hole/excitonblocking, preferably electron/exciton blocking, in devices is achieved,especially resulting in low voltages or long lifetimes.

The compounds of the present invention may be used in organic electronicdevices such as electrophotographic photoreceptors, photoelectricconverters, organic solar cells (organic photovoltaics), switchingelements, such as organic transistors, for example, organic FETs andorganic TFTs, organic light emitting field effect transistors (OLEFETs),image sensors, dye lasers and organic electroluminescent devices, forexample, organic light-emitting diodes (OLEDs).

Accordingly, a further subject of the present invention is directed toan organic electronic device, comprising a compound according to thepresent invention. The organic electronic device is preferably anelectroluminescent device (EL device), such as an organic light-emittingdiode (OLED).

The compounds of formula (I) can in principal be used in any layer of anEL device, but are preferably used as host, charge transport, i.e. holetransport or electron transport, and/or charge/exciton blocking, i.e.electron/exciton blocking or hole/exciton blocking, material.Particularly, the compounds of formula (I) are used as host material,preferably for green or red light emitting phosphorescence orfluorescence emitters, preferably phosphorescence emitters. In a furtherembodiment, the compounds of formula (I) are used as hole transportmaterials, preferably in devices comprising blue, green or red lightemitting phosphorescence or fluorescence emitters, preferablyfluorescence emitters.

Hence, a further subject of the present invention is directed to anemitting layer, comprising a compound of formula (I) according to thepresent invention. In said embodiment a compound of formula (I) ispreferably used as host material or as co-host material together withone or more, preferably one, further host materials. More preferably, acombination of a compound of formula (I) as host material or as co-hostmaterial together with a phosphorescent emitter is used.

The terms aromatic hydrocarbon group having 6 to 30 ring carbon atoms,heterocyclic group having 5 to 30 ring atoms, alkyl group having 1 to 30carbon atoms, alkenyl group having 2 to 30 carbon atoms, alkynyl grouphaving 1 to 30 carbon atoms, cycloalkyl group having 3 to 25 carbonatoms, aralkyl group having 7 to 24 carbon atoms, alkylene group having1 to 30 carbon atoms, cycloalkylene group having a ring structure formedof 3 to 20 carbon atoms, divalent silyl group having 2 to 20 carbonatoms, divalent aromatic hydrocarbon group having a ring structureformed of 6 to 30 carbon atoms, divalent heterocyclic group having aring structure formed of 5 to 30 atoms, silyl group, halogen atom,alkoxy group having 1 to 25 carbon atoms, haloalkyl group having 1 to 20carbon atoms, haloalkoxy group having 1 to 20 carbon atoms, aryloxygroup having 6 to 30 ring carbon atoms, alkylthio group having 1 to 20carbon atoms, arylthio group having 6 to 30 ring carbon atoms

are known in the art and generally have the following meaning, if saidgroups are not further specified in specific embodiments mentionedbelow:

The aromatic hydrocarbon group having 6 to 30 ring carbon atoms,preferably 6 to 24 ring carbon atoms, more preferably a substituted orunsubstituted aryl group having 6 to 24 carbon atoms, may be anon-condensed aromatic hydrocarbon group or a condensed aromatichydrocarbon group. Specific examples thereof include phenyl group,naphthyl group, phenanthryl group, biphenyl group, terphenyl group,quaterphenyl group, fluoranthenyl group, triphenylenyl group,phenanthrenyl group, fluorenyl group, spirofluorenyl group,9,9-diphenylfluorenyl group, 9,9′-spirobi[9H-fluorene]-2-yl group,9,9-dimethylfluorenyl group, benzo[c]phenanthrenyl group,benzo[a]triphenylenyl group, naphtho[1,2-c]phenanthrenyl group,naphtho[1,2-a]triphenylenyl group, dibenzo[a,c]triphenylenyl group, andbenzo[b]fluoranthenyl group, with phenyl group, naphthyl group, biphenylgroup, terphenyl group, phenanthryl group, triphenylenyl group,fluorenyl group, spirobifluorenyl group, and fluoranthenyl group beingpreferred, and phenyl group, 1-naphthyl group, 2-naphthyl group,biphenyl-2-yl group, biphenyl-3-yl group, biphenyl-4-yl group,phenanthrene-9-yl group, phenanthrene-3-yl group, phenanthrene-2-ylgroup, triphenylene-2-yl group, 9,9-dimethylfluorene-2-yl group,fluoranthene-3-yl group being more preferred.

The heterocyclic group having 5 to 30 ring atoms, preferably 5 to 18ring atoms, may be a non-condensed heterocyclic group or a condensedheterocyclic group. Specific examples thereof include the residues ofpyrrole ring, isoindole ring, benzofuran ring, isobenzofuran ring,dibenzothiophene ring, isoquinoline ring, quinoxaline ring,phenanthridine ring, phenanthroline ring, pyridine ring, pyrazine ring,pyrimidine ring, pyridazine ring, triazine ring, indole ring, quinolinering, acridine ring, pyrrolidine ring, dioxane ring, piperidine ring,morpholine ring, piperazine ring, carbazole ring, furan ring, thiophenering, oxazole ring, oxadiazole ring, benzoxazole ring, thiazole ring,thiadiazole ring, benzothiazole ring, triazole ring, imidazole ring,benzimidazole ring, pyran ring, dibenzofuran ring, andbenzo[c]dibenzofuran ring, and the residues of derivatives of theserings, with the residues of dibenzofuran ring, carbazole ring,dibenzothiophene ring, and derivatives of these rings being preferred,and the residues of dibenzofuran-2-yl group, dibenzofuran-4-yl group,9-phenylcarbazole-3-yl group, 9-phenylcarbazole-2-yl group,dibenzothiophene-2-yl group, and dibenzothiophene-4-yl group being morepreferred.

Examples of the alkyl group having 1 to 30 carbon atoms, preferablyhaving 1 to 25 carbon atoms, include methyl group, ethyl group, n-propylgroup, isopropyl group, n-butyl group, s-butyl group, isobutyl group,t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octylgroup, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group,n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecylgroup, n-heptadecyl group, n-octadecyl group, neopentyl group,1-methylpentyl group, with methyl group, ethyl group, n-propyl group,isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butylgroup being preferred.

Examples of the alkenyl group having 1 to 30 carbon atoms, preferablyhaving 1 to 25 carbon atoms, include ethenyl group, n-propenyl group,n-butenyl group, s-butenyl group, n-pentenyl group, n-hexenyl group,n-heptenyl group, n-octenyl group, n-nonenyl group, n-decenyl group,n-undecenyl group, n-dodecenyl group, n-tridecenyl group, n-tetradecenylgroup, n-pentadecenyl group, n-hexadecenyl group, n-heptadecenyl group,n-octadecenyl group, neopentenyl group, 1-methylpentenyl group, withethenyl group, n-propenyl group, n-butenyl group, s-butenyl group beingpreferred.

Examples of the alkynyl group having 1 to 30 carbon atoms, preferablyhaving 1 to 25 carbon atoms, include ethynyl group, n-propynyl group,n-butynyl group, s-butynyl group, n-pentynyl group, n-hexynyl group,n-heptynyl group, n-octynyl group, n-nonynyl group, n-decynyl group,n-undecynyl group, n-dodecynyl group, n-tridecynyl group, n-tetradecynylgroup, n-pentadecynyl group, n-hexadecynyl group, n-heptadecynyl group,n-octadecynyl group, neopentynyl group, 1-methylpentynyl group, withethynyl group, n-propynyl group, n-butynyl group, s-butynyl group beingpreferred.

Examples of the cycloalkyl group having 3 to 25 carbon atoms, preferablyhaving 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group,cyclopentyl group, cyclohexyl group, cyclooctyl group, and adamantylgroup, with cyclopentyl group, and cyclohexyl group being preferred.

Examples of an aralkyl group having 7 to 24 carbon atoms, preferably 7to 20 carbon atoms, include benzyl group, 2-phenylpropane-2-yl group,1-phenylethyl group, 2-phenylethyl group, 1-phenylisopropyl group,2-phenylisopropyl group, phenyl-t-butyl group, α-naphthylmethyl group,1-α-naphthylethyl group, 2-α-naphthylethyl group, 1-α-naphthylisopropylgroup, 2-α-naphthylisopropyl group, p-naphthylmethyl group,1-β-naphthylethyl group, 2-β-naphthylethyl group, 1-β-naphthylisopropylgroup, 2-β-naphthylisopropyl group, 1-pyrrolylmethyl group,2-(1-pyrrolyl)ethyl group, p-methylbenzyl group, m-methylbenzyl group,o-methylbenzyl group, p-chlorobenzyl group, m-chlorobenzyl group,o-chlorobenzyl group, p-bromobenzyl group, m-bromobenzyl group,o-bromobenzyl group, p-iodobenzyl group, m-iodobenzyl group,o-iodobenzyl group, p-hydroxybenzyl group, m-hydroxybenzyl group,o-hydroxybenzyl group, p-aminobenzyl group, m-aminobenzyl group,o-aminobenzyl group, p-nitrobenzyl group, m-nitrobenzyl group,o-nitrobenzyl group, p-cyanobenzyl group, m-cyanobenzyl group,o-cyanobenzyl group, 1-hydroxy-2-phenyl isopropyl group, and1-chloro-2-phenylisopropyl group.

Examples of the alkylene group (i.e. alkane-diyl group) having 1 to 30carbon atoms include methylene group, ethylene group, n-propylene group,isopropylene group, n-butylene group, s-butylene group, isobutylenegroup, t-butylene group, n-pentylene group, n-hexylene group,n-heptylene group, n-octylene group, n-nonylene group, n-decylene group,n-undecylene group, n-dodecylene group, n-tridecylene group,n-tetradecylene group, n-pentadecylene group, n-hexadecylene group,n-heptadecylene group, n-octadecylene group, neopentylene group,1-methylpentylene group, with methylene group, ethylene group,n-propylene group, isopropylene group, n-butylene group, s-butylenegroup, isobutylene group, t-butylene group being preferred.

Examples of the cycloalkylene group (i.e. cycloalkane-diyl group) having3 to 20 carbon atoms include cyclopropylene group, cyclobutylene group,cyclopentylene group, cyclohexylene group, cyclooctylene group, andadamantylene group, with cyclopentylene group, and cyclohexylene groupbeing preferred.

Examples of the divalent silyl group having 2 to 20 carbon atoms includedivalent dimethylsilyl group, divalent diethylsilyl group, divalentdibutylsilyl group, divalent methylethylsilyl group, divalentt-butylmethylsilyl group, divalent vinylmethylsilyl group, divalentpropylmethylsilyl group, divalent methylisopropylsilyl group, divalentmethylpropylsilyl group, divalent methylbutylsilyl group, divalentmethyltertiarybutylsilyl group, divalent ethylisopropylsilyl group,divalent phenylmethylsilyl group, divalent phenylmethylsilyl group,divalent phenyltertiarybutylsilyl group, and divalent diphenylsilylgroup, with divalent dimethylsilyl group, divalent diethylsilyl group,divalent t-butylmethylsilyl group, divalent vinylmethylsilyl group, anddivalent propylmethylsilyl group being preferred.

The divalent aromatic hydrocarbon group having 6 to 30 ring carbonatoms, preferably having 6 to 24 ring carbon atoms (arylene group having6 to 24 carbon atoms) may be a non-condensed divalent aromatichydrocarbon group or a condensed divalent aromatic hydrocarbon group.

Specific examples thereof include phenylene group, naphthylene group,phenanthrylene group, biphenyl-diyl group, terphenyl-diyl group,quaterphenyl-diyl group, fluoranthen-diyl group, triphenylenylene-diylgroup, phenanthrene-diyl group, fluorene-diyl group, spirofluorene-diylgroup, 9,9-diphenylfluorene-diyl group, 9,9′-spirobi[9H-fluorene]-2-diylgroup, 9,9-dimethylfluorene-diyl group, benzo[c]phenanthrene-diyl group,benzo[a]triphenylene-diyl group, naphtho[1,2-c]phenanthrene-diyl group,naphtho[1,2-a]triphenylenylene-diyl group,dibenzo[a,c]triphenylenylene-diyl group, and benzo[b]fluoranthene-diylgroup, with phenylene group, naphthylene group, biphenyl-diyl group,terphenyl-diyl group, phenanthryl-diyl group, triphenylenylen-diylgroup, fluorene-diyl group, spirobifluorene-diyl group, andfluoranthene-diyl group being preferred, and 1,2-phenylene group,1,3-phenylene group, 1,4-phenylene group, 1,4-naphthylene group,1,8-naphthylene group, 2,6-naphthylene group, 2,7-naphthylene group,biphenyl-2,2′-diyl group, biphenyl-2,3′-diyl group, biphenyl-2,4′-diylgroup, biphenyl-2,5′-diyl group, biphenyl-2,6′-diyl group,biphenyl-3,3′-diyl group, biphenyl-3,4′-diyl group, biphenyl-3,5′-diylgroup, biphenyl-3,6′-diyl group, biphenyl-4,4′-diyl group,biphenyl-4,5′-diyl group, biphenyl-4,6′-diyl group, biphenyl-5,5′-diylgroup, biphenyl-5,6′-diyl group, biphenyl-6,6′-diyl group,phenanthrene-9,10-diyl group, phenanthrene-2,3-diyl group,phenanthrene-2,7-diyl group, phenanthrene-2,8-diyl group,phenanthrene-2,6-diyl group, phenanthrene-2,9-diyl group,phenanthrene-2,10-diyl group, phenanthrene-3,9-diyl group,phenanthrene-3,10-diyl group, triphenylene-2,3-diyl group,triphenylene-2,5-diyl group, triphenylene-2,6-diyl group,triphenylene-2,7-diyl group, triphenylene-2,8-diyl group,9,9-dimethylfluorene-2,7-diyl group, 9,9-dimethylfluorene-3,7-diylgroup, 9,9-dimethylfluorene-1,4-diylgroup, fluoranthene-3,9-diyl group,fluoranthene-3,8-diyl group, fluoranthene-3,4-diyl group,fluoranthene-3,5-diyl group, fluoranthene-3,6-diyl group,fluoranthene-2,9-diyl group, fluoranthene-2,8-diyl group,fluoranthene-2,4-diyl group, fluoranthene-2,5-diyl group,fluoranthene-2,6-diyl group, fluoranthene-1,9-diylgroup,fluoranthene-1,8-diylgroup, fluoranthene-1,4-diylgroup,fluoranthene-1,5-diylgroup, fluoranthene-1,6-diylgroup being morepreferred.

The divalent heterocyclic group having 5 to 30 ring atoms may be anon-condensed heterocyclic group or a condensed heterocyclic group.Specific examples thereof include the divalent residues of pyrrole ring,isoindole ring, benzofuran ring, isobenzofuran ring, dibenzothiophenering, isoquinoline ring, quinoxaline ring, phenanthridine ring,phenanthroline ring, pyridine ring, pyrazine ring, pyrimidine ring,pyridazine ring, triazine ring, indole ring, quinoline ring, acridinering, pyrrolidine ring, dioxane ring, piperidine ring, morpholine ring,piperazine ring, carbazole ring, furan ring, thiophene ring, oxazolering, oxadiazole ring, benzoxazole ring, thiazole ring, thiadiazolering, benzothiazole ring, triazole ring, imidazole ring, benzimidazolering, pyran ring, dibenzofuran ring, and benzo[c]dibenzofuran ring, andthe divalent residues of derivatives of these rings, with the divalentresidues of dibenzofuran ring, carbazole ring, dibenzothiophene ring,and derivatives of these divalent rings being preferred, and thedibenzofuran-diyl group, 9-phenylcarbazole-diyl group anddibenzothiophene-diyl group being more preferred.

Examples of silyl groups (alkyl or aryl substituted silyl groups)include alkylsilyl groups having 1 to 10 carbon atoms, preferably 1 to 5carbon atoms, including trimethylsilyl group, triethylsilyl group,tributylsilyl group, dimethylethylsilyl group, t-butyldimethylsilylgroup, vinyldimethylsilyl group, propyldimethylsilyl group,dimethylisopropylsilyl group, dimethylpropylsilyl group,dimethylbutylsilyl group, dimethyltertiarybutylsilyl group,diethylisopropylsilyl group, and arylsilyl groups having 6 to 30 carbonatoms, preferably 6 to 18 carbon atoms, including phenyldimethylsilylgroup, diphenylmethylsilyl group, diphenyltertiarybutylsilyl group, andtriphenylsilyl group, with trimethylsilyl group, triethylsilyl group,t-butyldimethylsilyl group, vinyldimethylsilyl group, andpropyldimethylsilyl group being preferred.

Examples of halogen atoms include fluorine, chlorine, bromine, andiodine, with fluorine being preferred.

Examples of an alkoxy group having 1 to 25 carbon atoms, preferablyhaving 1 to 20 carbon atoms, include those having an alkyl portionselected from the alkyl groups mentioned above.

Examples of a haloalkyl group having 1 to 20 carbon atoms include thealkyl groups mentioned above wherein the hydrogen atoms thereof arepartly or entirely substituted by halogen atoms.

Examples of a haloalkoxy group having 1 to 20 carbon atoms include thealkoxyl group mentioned above wherein the hydrogen atoms thereof arepartly or entirely substituted by halogen atoms.

Examples of an aryloxy group having 6 to 30 ring carbon atoms,preferably having 6 to 24 carbon atoms include those having an arylportion selected from the aromatic hydrocarbon groups mentioned above.

Examples of an alkylthio group having 1 to 25 carbon atoms, preferablyhaving 1 to 20 carbon atoms include those having an alkyl portionselected from the alkyl groups mentioned above.

Examples of an arylthio group having 6 to 30 ring carbon atoms,preferably having 6 to 24 carbon atoms include those having an arylportion selected from the aromatic hydrocarbon groups mentioned above.

Examples of an alkyl or aryl substituted carbonyl group (—(C═O)R*include those, wherein R* is an alkyl group having 1 to 30 carbon atomsor a aromatic hydrocarbon group having 6 to 30 ring carbon atoms,preferably R* is a methyl group, ethyl group, n-propyl group, isopropylgroup, n-butyl group, s-butyl group, isobutyl group, t-butyl group,phenyl group, 1-naphthyl group or 2-naphthyl group.

Examples of a substituted phosphoryl group (—P(═O)(OR**)₂) includethose, wherein R** is an alkyl group having 1 to 30 carbon atoms or aaromatic hydrocarbon group having 6 to 30 ring carbon atoms, preferablyR** is a methyl group, ethyl group, n-propyl group, isopropyl group,n-butyl group, s-butyl group, isobutyl group, t-butyl group, phenylgroup, 1-naphthyl group or 2-naphthyl group.

Examples of the optional substituent(s) indicated by “substituted orunsubstituted” and “may be substituted” referred to above or hereinafterinclude a halogen atom (fluorine, chlorine, bromine, iodine), a cyanogroup, an alkyl group having 1 to 30, preferably 1 to 6 carbon atoms, acycloalkyl group having 3 to 20, preferably 5 to 12 carbon atoms, analkoxyl group having 1 to 20, preferably 1 to 5 carbon atoms, ahaloalkyl group having 1 to 20, preferably 1 to 5 carbon atoms, ahaloalkoxyl group having 1 to 20, preferably 1 to 5 carbon atoms, asilyl group, an aromatic hydrocarbon group having 6 to 30 ring carbonatoms, preferably 6 to 18 ring carbon atoms, an aryloxy group having 6to 30, preferably 6 to 18 ring carbon atoms, an aralkyl group having 7to 24, preferably 7 to 20 carbon atoms, an alkylthio group having 1 to20, preferably 1 to 5 carbon atoms, an arylthio group having 6 to 30,preferably 6 to 18 ring carbon atoms, and a heterocyclic group having 5to 30 ring atoms, preferably 5 to 18 ring atoms.

The optional substituent is preferably a fluorine atom, a cyano group,an alkyl group having 1 to 30 carbon atoms, an aromatic hydrocarbongroup having 6 to 30 ring carbon atoms, preferably 6 to 18 ring carbonatoms, and an heterocyclic group having 5 to 30 ring atoms, preferably 5to 18 ring atoms; more preferably a fluorine atom, a phenyl group, anaphthyl group, a biphenyl group, a terphenyl group, a phenanthrylgroup, a triphenylenyl group, a fluorenyl group, a spirobifluorenylgroup, a fluoranthenyl group, a residue based on a dibenzofuran ring, aresidue based on a carbazole ring, a residue based on a dibenzothiophenering, and their derivatives, a methyl group, an ethyl group, an n-propylgroup, an isopropyl group, an n-butyl group, an s-butyl group, anisobutyl group, a t-butyl group, a cyclopentyl group, and a cyclohexylgroup.

The optional substituent mentioned above may be further substituted byone or more of the optional substituents mentioned above.

The number of the optional substituents depends on the group which issubstituted by said substituent(s). Preferred are 1, 2, 3 or 4 optionalsubstituents, more preferred are 1, 2 or 3 optional substituents, mostpreferred are 1 or 2 optional substituents. In a further preferredembodiment, the groups mentioned above are unsubstituted.

The “carbon number of a to b” in the expression of “substituted orunsubstituted X group having a to b carbon atoms” is the carbon numberof the unsubstituted X group and does not include the carbon atom(s) ofan optional substituent.

The hydrogen atom referred to herein includes isotopes different fromneutron numbers, i.e., light hydrogen (protium), heavy hydrogen(deuterium) and tritium.

The group of formula

In the Group of Formula

which is a part of formula (I),

X_(A) and X_(B) each independently represent O or S, preferably O;

r represents 1, 2 or 3; in the case that r is 2 or 3, X_(B) as well asAr₃ are the same or different in each occurrence, preferably r is 1; and

Ar₁, Ar₂ and Ar₃ each independently represent a substituted orunsubstituted aromatic hydrocarbon group having a ring structure formedof 6 to 30 carbon atoms or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms, and which islinked to one aromatic hydrocarbon group of Ar₁, Ar₂ respectively Ar₃via a carbon-carbon bond; preferably, Ar₁, Ar₂ and Ar₃ eachindependently represent a substituted or unsubstituted aromatichydrocarbon group having a ring structure formed of 6 to 10 carbon atomsor a substituted or unsubstituted aromatic heterocyclic group having aring structure formed of 6 to 13 atoms;

more preferably, Ar₁, Ar₂ and Ar₃ each independently represent asubstituted or unsubstituted aromatic hydrocarbon group having a ringstructure formed of 6 to 10 carbon atoms.

Preferred suitable optional substituents of Ar₁, Ar₂ and Ar₃ are in eachoccurrence independently a substituted or unsubstituted alkyl grouphaving 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkylgroup having a ring formed of 3 to 20 carbon atoms, a substituted orunsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted orunsubstituted aralkyl group having 7 to 24 carbon atoms, a silyl grouphaving 3 to 20 carbon atoms, a substituted or unsubstituted aromatichydrocarbon group having ring structure formed of 6 to 30 carbon atomsor a substituted or unsubstituted heterocyclic group having a ringstructure formed of 5 to 30 atoms, or a substituted or unsubstitutedalkylthio group having 1 to 20 carbon atoms, or a substituted orunsubstituted arylthio group having 6 to 30 carbon atoms, or asubstituted or unsubstituted aryloxy group having 6 to 30 carbon atoms,a cyano group or a halogen atom; provided that, in the case of twoadjacent substituents, said adjacent substituents may be bonded eachother to form ring structures;

more preferred suitable optional substituents of Ar₁, Ar₂ and Ar₃ are ineach occurrence independently a substituted or unsubstituted aromatichydrocarbon group having ring structure formed of 6 to 30 carbon atomsor a substituted or unsubstituted heterocyclic group having a ringstructure formed of 5 to 30 atoms;

most preferred suitable optional substituents of Ar₁, Ar₂ and Ar₃ are ineach occurrence independently a substituted or unsubstituted aromatichydrocarbon group having ring structure formed of 6 to 18 carbon atoms.

The total number of the optional substituents of Ar₁, Ar₂ and Ar₃ ispreferably 1, 2, 3, 4 or 5, more preferably 1, 2 or 3, most preferably 1or 2 and further most preferably 1.

Most preferred groups (I*) are therefore the following groups:

wherein

X²¹ to X³⁰ each independently represent CR_(X) or N, preferably CR_(X);

R_(x) is in each occurrence independently H, a substituted orunsubstituted alkyl group having 1 to 30 carbon atoms, a substituted orunsubstituted cycloalkyl group having a ring formed of 3 to 20 carbonatoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbonatoms, a substituted or unsubstituted aralkyl group having 7 to 24carbon atoms, a silyl group having 3 to 20 carbon atoms, a substitutedor unsubstituted aromatic hydrocarbon group having ring structure formedof 6 to 30 carbon atoms or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms, or a substitutedor unsubstituted alkylthio group having 1 to 20 carbon atoms, or asubstituted or unsubstituted arylthio group having 6 to 30 carbon atoms,or a substituted or unsubstituted aryloxy group having 6 to 30 carbonatoms, a cyano group or a halogen atom;

provided that, among X²¹ to X³⁰, if two or more atoms are CR_(X), anytwo of CR_(X)s may be bonded each other to form ring structures;

preferably, R_(x) is in each occurrence independently H, a substitutedor unsubstituted aromatic hydrocarbon group having ring structure formedof 6 to 30 carbon atoms or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms;

provided that, among X²¹ to X³⁰, if two or more atoms are CR_(X), anytwo of CR_(X)s may be bonded each other to form ring structures;

more preferably, R_(x) is in each occurrence independently H, asubstituted or unsubstituted aromatic hydrocarbon group having ringstructure formed of 6 to 18 carbon atoms;

provided that, among X²¹ to X³⁰, if two or more atoms are CR_(X), anytwo of CR_(X)s may be bonded each other to form ring structures;

wherein one of X²¹ to X³⁰ in each formula (I*a), (I*b), (I*c), (I*d) and(I*e) represents a bonding site to -(L)_(m)-A via a carbon atom.

Most preferred compounds are compounds (I*a), (I*b), (I*c) and (I*d),further most preferred are compounds (I*a), (I*b) and (I*c).

The Group -(L)_(m)-A

L represents a single bond, a substituted or unsubstituted alkylenegroup having 1 to 30 carbon atoms, a substituted or unsubstitutedcycloalkylene group having a ring structure formed of 3 to 20 carbonatoms, a divalent silyl group having 2 to 20 carbon atoms, a substitutedor unsubstituted divalent aromatic hydrocarbon group having a ringstructure formed of 6 to 30 carbon atoms or a substituted orunsubstituted divalent heterocyclic group having a ring structure formedof 5 to 30 atoms;

preferably, L represents a single bond, an alkylene group having 1 to 20carbon atoms, a substituted or unsubstituted cycloalkylene group havinga ring formed of 3 to 20 carbon atoms, a divalent silyl group or adivalent silyl group having 2 to 20 carbon atoms, a substituted orunsubstituted, divalent aromatic hydrocarbon group having a ringstructure formed of 6 to 24 carbon atoms, or a substituted orunsubstituted, divalent aromatic heterocyclic group having a ringstructure formed of 5 to 24 atoms, which is linked with the group

through a carbon-carbon bond;

more preferably, L is a single bond, 1,3-diphenylene, 1,4-diphenylene,1,2-diphenylene, biphenylene, divalent dibenzofuran, divalentdibenzothiophen, divalent substituted carbazole or divalent9-phenylcarbazole;

most preferably, L is a single bond.

m is 1, 2 or 3; in the case that m is 2 or 3, L is the same or differentin each occurrence, preferably m is 1.

A is

wherein the dotted line is a bonding site to L, and R¹⁷ is a substitutedor unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbonatoms or a substituted or unsubstituted heterocyclic group having 5 to30 ring atoms, an alkyl group having 1 to 20 carbon atoms, a substitutedor unsubstituted cycloalkyl group having a ring formed of 3 to 20 carbonatoms, a substituted or unsubstituted aralkyl group having 7 to 24carbon atoms;

L₁ is a single bond, a substituted or unsubstituted alkylene grouphaving 1 to 30 carbon atoms, a substituted or unsubstitutedcycloalkylene group having a ring structure formed of 3 to 20 carbonatoms, a substituted divalent silyl group having 2 to 20 carbon atoms, asubstituted or unsubstituted divalent aromatic hydrocarbon group havinga ring structure formed of 6 to 30 carbon atoms, or a substituted orunsubstituted divalent heterocyclic group having a ring structure formedof 5 to 30 atoms;

n is 1, 2 or 3; in the case that n is 2 or 3, L₁ is the same ordifferent in each occurrence;

Ar₄, Ar₅, Ar₆ and Ar₇ each independently represent a substituted orunsubstituted aromatic hydrocarbon group having a ring structure formedof 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms.

Suitable and preferred groups A are defined below.

The Group of Formula

The groups and indices Ar₁, Ar₂, Ar₃, X_(A), X_(B), r, L, m and A havebeen described above, and preferred groups A are additionally describedbelow.

More preferred groups of formula (I) have one of the following formulae:

wherein the groups and indices X²¹ to X³⁰, X_(A), X_(B), L, m and A havebeen described above, and preferred groups A are additionally describedbelow,

wherein one of X²⁷ to X³⁰ in each formula (Ia), (Ib), (Ic), (Id), (Ij)one of X²⁵ to X²⁶ in each formula (Ie), (If), (Ig), (Ih), (Ii) and oneof X²¹ to X²⁴ in formula (Ib′) represents a bonding site to -(L)_(m)-Avia a carbon atom.

Most preferred compounds are compounds (Ia), (Ib), (Ib′), (Ic), (Id),(Ig) and (If), further most preferred are compounds (Ia), (Ib), (Ib′)and (Ic).

Preferably, as mentioned above, X²¹ to X³⁰ each independently representCR_(X). Most preferred compounds of formula (I) therefore have one ofthe following formulae:

wherein

X_(A), X_(B), L, m and A have been described above, and preferred groupsA are additionally described below,

R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰ are in eachoccurrence independently H, a substituted or unsubstituted alkyl grouphaving 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkylgroup having a ring formed of 3 to 20 carbon atoms, a substituted orunsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted orunsubstituted aralkyl group having 7 to 24 carbon atoms, a silyl grouphaving 3 to 20 carbon atoms, a substituted or unsubstituted aromatichydrocarbon group having ring structure formed of 6 to 30 carbon atomsor a substituted or unsubstituted heterocyclic group having a ringstructure formed of 5 to 30 atoms, or a substituted or unsubstitutedalkylthio group having 1 to 20 carbon atoms, or a substituted orunsubstituted arylthio group having 6 to 30 carbon atoms, or asubstituted or unsubstituted aryloxy group having 6 to 30 carbon atoms,a cyano group or a halogen atom; provided that, two adjacent residues ofthe residues R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰ may bebonded each other to form ring structures;

preferably, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰ are ineach occurrence independently H, a substituted or unsubstituted aromatichydrocarbon group having ring structure formed of 6 to 30 carbon atomsor a substituted or unsubstituted heterocyclic group having a ringstructure formed of 5 to 30 atoms;

provided that, two adjacent residues of the residues R²¹, R²², R²³, R²⁴,R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰ may be bonded each other to form ringstructures;

more preferably, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰ arein each occurrence independently H, a substituted or unsubstitutedaromatic hydrocarbon group having ring structure formed of 6 to 18carbon atoms;

provided that, two adjacent residues of the residues R²¹, R²², R²³, R²⁴,R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰ may be bonded each other to form ringstructures;

wherein one of R²⁷ to R³⁰ in each formula (Ia-1), (Ib-1), (Ic-1),(Id-1), (Ij-1) one of R²⁵ to R²⁶ in each formula (Ie-1), (If-1), (Ig-1),(Ih-1), (Ii-1) and one of R²¹ to R²⁴ in formula (Ib′-1) represents abonding to -(L)_(m)-A via a carbon atom.

Most preferred compounds are compounds (Ia-1), (Ib-1), (Ib′-1), (Ic-1),(Id-1), (Ig-1) and (If-1), further most preferred are compounds (Ia-1),(Ib-1) and (Ic-1).

Preferably, the bonding site to -(L)_(m)-A is at the position R²⁹ or R²⁷in each formula (Ia-1), (Ib-1), (Ic-1), (Id-1), (Ij-1) R²⁵ or R²⁶ ineach formula (Ie-1), (If-1), (Ig-1), (Ih-1), (Ii-1) and R²² or R²⁴ informula (Ib′-1).

Further most preferred compounds of formula (I) are compounds (Ia-1),(Ib-1), (Ib′-1), (Ic-1), (Id-1), (Ig-1) and (If-1), wherein the bondingsite to -(L)_(m)-A is at the position R²⁹ or R²⁷ in formula (Ia-1),(Ib-1), (Ic-1) and (Id-1), at the position R²⁵ or R²⁶ in formula (Ig-1)and (If-1) and at the position R²² or R²⁴ in formula (Ib′-1).

Even further most preferred are compounds (Ia-1), (Ib-1) and (Ic-1),wherein the bonding site to -(L)_(m)-A is at the position R²⁹ or R²⁷.Even further preferred are compounds (Ia-1), (Ib-1) and (Ic-1), whereinthe bonding site to -(L)_(m)-A is at the position R²⁹.

The residues R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰ whichdo not represent a bonding to -(L)_(m)-A are defined above. Preferably,0, 1, 2 or 3, more preferably 0, 1 or 2, most preferably 0 or 1 andfurther most preferably 0 of the residues R²¹, R²², R²³, R²⁴, R²⁵, R²⁶,R²⁷, R²⁸, R²⁹ and R³⁰ which do not represent a bonding to -(L)_(m)-A arenot H and the remaining residues R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸,R²⁹ and R³⁰ which do not represent a bonding to -(L)_(m)-A are H.

Preferably, 0, 1, 2 or 3, more preferably 0, 1 or 2, most preferably 0or 1 and further most preferably 0 of the residues R²¹, R²², R²³, R²⁴,R²⁵ and R²⁶ in each formula (Ia-1), (Ib-1), (Ic-1), (Id-1), (Ij-1) arenot H; 0, 1, 2 or 3, more preferably 0, 1 or 2, most preferably 0 or 1and further most preferably 0 of the residues R²¹, R²², R²³, R²⁴, R²⁷,R²⁸, R²⁹ and R³⁰ in each formula (Ie-1), (If-1), (Ig-1), (Ih-1), (Ii-1)are not H and 0, 1, 2 or 3, more preferably 0, 1 or 2, most preferably 0or 1 and further most preferably 0 of the residues R²⁵, R²⁶, R²⁷, R²⁸,R²⁹ and R³⁰ in formula (Ib′-1) are not H. All other residues R²¹, R²²,R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰ in the compounds of formulae(Ia-1), (Ib-1), (Ic-1), (Id-1), (Ie-1), (If-1), (Ig-1), (Ih-1), (Ii-1),(Ij-1) and (Ib′-1) which do not represent a bonding to -(L)_(m)-A arepreferably H.

In one preferred embodiment, all residues R², R²², R²³, R²⁴, R²⁵, R²⁶,R²⁷, R²⁸, R²⁹ and R³⁰ in the compounds of formulae (Ia-1), (Ib-1),(Ic-1), (Id-1), (Ie-1), (If-1), (Ig-1), (Ih-1), (Ii-1), (Ij-1) and(Ib′-1) which do not represent a bonding to -(L)_(m)-A are H.

Especially preferred compounds of formula (I) have one of the followingformulae:

wherein

R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰, X_(A), X_(B), m andA have been described above, and preferred groups A are additionallydescribed below.

The Group of Formula A

A is

wherein the dotted line is a bonding site to L, and R¹⁷ is a substitutedor unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbonatoms or a substituted or unsubstituted heterocyclic group having 5 to30 ring atoms, an alkyl group having 1 to 20 carbon atoms, a substitutedor unsubstituted cycloalkyl group having a ring formed of 3 to 20 carbonatoms, a substituted or unsubstituted aralkyl group having 7 to 24carbon atoms;

L₁ is a single bond, a substituted or unsubstituted alkylene grouphaving 1 to 30 carbon atoms, a substituted or unsubstitutedcycloalkylene group having a ring structure formed of 3 to 20 carbonatoms, a substituted divalent silyl group having 2 to 20 carbon atoms, asubstituted or unsubstituted divalent aromatic hydrocarbon group havinga ring structure formed of 6 to 30 carbon atoms, or a substituted orunsubstituted divalent heterocyclic group having a ring structure formedof 5 to 30 atoms;

n is 1, 2 or 3; in the case that n is 2 or 3, L₁ is the same ordifferent in each occurrence;

Ar₄, Ar₅, Ar₆ and Ar₇ each independently represent a substituted orunsubstituted aromatic hydrocarbon group having a ring structure formedof 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms.

R¹⁷ is preferably a substituted or unsubstituted non-condensed aromatichydrocarbon group or a substituted or unsubstituted condensed aromatichydrocarbon group, for example including phenyl group, naphthyl group,phenanthryl group, biphenyl group, terphenyl group, quaterphenyl group,fluoranthenyl group, triphenylenyl group, phenanthrenyl group, fluorenylgroup, spirofluorenyl group, 9,9-diphenylfluorenyl group,9,9′-spirobi[9H-fluorene]-2-yl group, 9,9-dimethylfluorenyl group,benzo[c]phenanthrenyl group, benzo[a]triphenylenyl group,naphtho[1,2-c]phenanthrenyl group, naphtho[1,2-a]triphenylenyl group,dibenzo[a,c]triphenylenyl group, and benzo[b]fluoranthenyl group, withphenyl group, naphthyl group, biphenyl group, terphenyl group,phenanthryl group, triphenylenyl group, fluorenyl group,spirobifluorenyl group, and fluoranthenyl group being preferred, andphenyl group, 1-naphthyl group, 2-naphthyl group, biphenyl-2-yl group,biphenyl-3-yl group, biphenyl-4-yl group, phenanthrene-9-yl group,phenanthrene-3-yl group, phenanthrene-2-yl group, triphenylene-2-ylgroup, 9,9-dimethylfluorene-2-yl group, fluoranthene-3-yl group beingmore preferred, wherein the groups mentioned before are unsubstituted orsubstituted;

a substituted or unsubstituted non-condensed heterocyclic group or asubstituted or unsubstituted condensed heterocyclic group, for exampleincluding the residues of pyrrole ring, isoindole ring, benzofuran ring,isobenzofuran ring, dibenzothiophene ring, isoquinoline ring,quinoxaline ring, phenanthridine ring, phenanthroline ring, pyridinering, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring,indole ring, quinoline ring, acridine ring, pyrrolidine ring, dioxanering, piperidine ring, morpholine ring, piperazine ring, carbazole ring,furan ring, thiophene ring, oxazole ring, oxadiazole ring, benzoxazolering, thiazole ring, thiadiazole ring, benzothiazole ring, triazolering, imidazole ring, benzimidazole ring, pyran ring, dibenzofuran ring,and benzo[c]dibenzofuran ring, and the residues of derivatives of theserings, with the residues of dibenzofuran ring, carbazole ring,dibenzothiophene ring, and derivatives of these rings being preferred,and the residues of dibenzofuran-2-yl group, dibenzofuran-4-yl group,9-phenylcarbazole-3-yl group, 9-phenylcarbazole-2-yl group,dibenzothiophene-2-yl group, and dibenzothiophene-4-yl group being morepreferred, wherein the groups mentioned before are unsubstituted orsubstituted;

methyl group, ethyl group, n-propyl group, isopropyl group, n-butylgroup, s-butyl group, isobutyl group, t-butyl group, n-pentyl group,n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decylgroup, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecylgroup, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group,n-octadecyl group, neopentyl group, 1-methylpentyl group, cyclopropylgroup, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclooctylgroup, and adamantyl group, with methyl group, ethyl group, n-propylgroup, isopropyl group, n-butyl group, s-butyl group, isobutyl group,t-butyl group, cyclopentyl group, and cyclohexyl group being preferred,wherein the groups mentioned before are unsubstituted or substituted;

benzyl group, 2-phenylpropane-2-yl group, 1-phenylethyl group,2-phenylethyl group, 1-phenylisopropyl group, 2-phenylisopropyl group,phenyl-t-butyl group, α-naphthylmethyl group, 1-α-naphthylethyl group,2-α-naphthylethyl group, 1-α-naphthylisopropyl group,2-α-naphthylisopropyl group, p-naphthylmethyl group, 1-β-naphthylethylgroup, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group,2-β-naphthylisopropyl group, 1-pyrrolylmethyl group, 2-(1-pyrrolyl)ethylgroup, p-methylbenzyl group, m-methylbenzyl group, o-methylbenzyl group,p-chlorobenzyl group, m-chlorobenzyl group, o-chlorobenzyl group,p-bromobenzyl group, m-bromobenzyl group, o-bromobenzyl group,p-iodobenzyl group, m-iodobenzyl group, o-iodobenzyl group,p-hydroxybenzyl group, m-hydroxybenzyl group, o-hydroxybenzyl group,p-aminobenzyl group, m-aminobenzyl group, o-aminobenzyl group,p-nitrobenzyl group, m-nitrobenzyl group, o-nitrobenzyl group,p-cyanobenzyl group, m-cyanobenzyl group, o-cyanobenzyl group,1-hydroxy-2-phenyl isopropyl group, and 1-chloro-2-phenylisopropylgroup, wherein the groups mentioned before are unsubstituted orsubstituted.

Suitable optional substituents and numbers of said optional substituentsare mentioned above.

L₁ is preferably a single bond, an alkylene group having 1 to 20 carbonatoms, a substituted or unsubstituted cycloalkylene group having a ringformed of 3 to 20 carbon atoms, a divalent silyl group or a divalentsilyl group having 2 to 20 carbon atoms, a substituted or unsubstituted,divalent aromatic hydrocarbon group having a ring structure formed of 6to 24 carbon atoms, or a substituted or unsubstituted, divalent aromaticheterocyclic group having a ring structure formed of 5 to 24 atoms,which is linked with the groups Ary and Ar₆ through a carbon-carbonbond;

more preferably, L₁ is a single bond, 1,3-diphenylene, 1,4-diphenylene,1,2-diphenylene, biphenylene, divalent dibenzofuran, divalentdibenzothiophen, divalent substituted carbazole or divalent9-phenylcarbazole;

most preferably, L₁ is a single bond.

Suitable optional substituents and numbers of said optional substituentsare mentioned above.

n is 1, 2 or 3; in the case that n is 2 or 3, L₁ is the same ordifferent in each occurrence. Preferably, n is 1 or 2, more preferably,n is 1.

Ar₄, Ar₅, Ar6 and Ar₇ each independently represent a substituted orunsubstituted aromatic hydrocarbon group having a ring structure formedof 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms.

Preferred groups Ar₄

are

preferred group Ar₅

are

preferred groups Ar₆

are

andpreferred groups Ar₇

are

wherein the dotted lines are bonding sites, and

X¹ to X⁸, and Y¹, to Y⁸ each independently represent CR_(Y) or N,preferably CR_(Y);

R_(Y) is in each occurrence independently H, a substituted orunsubstituted alkyl group having 1 to 30 carbon atoms, a substituted orunsubstituted cycloalkyl group having a ring formed of 3 to 20 carbonatoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbonatoms, a substituted or unsubstituted aralkyl group having 7 to 24carbon atoms, a silyl group having 3 to 20 carbon atoms, a substitutedor unsubstituted hydrocarbon group having ring structure formed of 6 to30 carbon atoms or a substituted or unsubstituted aromatic heterocyclicgroup having a ring structure formed of 5 to 30 atoms, or a substitutedor unsubstituted alkylthio group having 1 to 20 carbon atoms, or asubstituted or unsubstituted arylthio group having 6 to 30 carbon atoms,or a substituted or unsubstituted aryloxy group having 6 to 30 carbonatoms, a cyano group or a halogen atom;

provided that, among X¹ to X⁸ and Y¹ to Y⁸, if two or more atoms areCR_(Y), any two of CR_(Y)s may be bonded each other to form ringstructures

wherein one of X⁵, X⁶, X⁷ or X⁸ and one of Y¹, Y², Y³ or Y⁴, are bondedto each other via L₁.

Suitable optional substituents and numbers of said optional substituentsare mentioned above.

Therefore, A is preferably a group of the following formula:

X¹ to X⁸, and Y¹, to Y⁸ each independently represent CR_(Y) or N,preferably CR_(Y);

R_(Y) is in each occurrence independently H, a substituted orunsubstituted alkyl group having 1 to 30 carbon atoms, a substituted orunsubstituted cycloalkyl group having a ring formed of 3 to 20 carbonatoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbonatoms, a substituted or unsubstituted aralkyl group having 7 to 24carbon atoms, a silyl group having 3 to 20 carbon atoms, a substitutedor unsubstituted hydrocarbon group having ring structure formed of 6 to30 carbon atoms or a substituted or unsubstituted aromatic heterocyclicgroup having a ring structure formed of 5 to 30 atoms, or a substitutedor unsubstituted alkylthio group having 1 to 20 carbon atoms, or asubstituted or unsubstituted arylthio group having 6 to 30 carbon atoms,or a substituted or unsubstituted aryloxy group having 6 to 30 carbonatoms, a cyano group or a halogen atom;

provided that, among X¹, to X⁸ and Y¹ to Y⁸, if two or more atoms areCR_(Y), any two of CR_(Y)s may be bonded each other to form ringstructures

wherein one of X⁵, X⁶, X⁷ or X⁸ and one of Y¹, Y², Y³ or Y⁴, are bondedto each other via L₁.

Preferably, R_(Y) is in each occurrence independently H, a substitutedor unsubstituted alkyl group having 1 to 30 carbon atoms, a substitutedor unsubstituted aromatic hydrocarbon group having ring structure formedof 6 to 30 carbon atoms or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms; provided that,among X¹ to X⁸ and Y¹ to Y⁸, if two or more atoms are CR_(Y), any two ofCR_(Y)s may be bonded each other to form ring structures;

more preferably, R_(Y) is in each occurrence independently H, methylgroup, ethyl group, n-propyl group, isopropyl group, n-butyl group,s-butyl group, isobutyl group, t-butyl group, a substituted orunsubstituted aromatic hydrocarbon group having ring structure formed of6 to 18 carbon atoms, or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 18 atoms;

most preferably, R_(Y) is in each occurrence independently H, isopropylgroup, n-butyl group, s-butyl group, isobutyl group, t-butyl group,substituted or unsubstituted phenyl, substituted or unsubstitutedcarbazolyl, substituted or unsubstituted dibenzofuryl, substituted orunsubstituted dibenzothienyl, further most preferably R_(Y) is in eachoccurrence H.

Suitable optional substituents and numbers of said optional substituentsare mentioned above.

Preferably, in the group A, X¹, X², X³, X⁴, X⁵, X⁶, X⁷, X⁸, Y¹, Y², Y³,Y⁴, Y⁵, Y⁶, Y⁷ and Y⁸ is CR_(Y), wherein one of R_(Y) at one of thepositions X⁵ to X⁸ and one of R_(Y) at the positions Y¹, to Y⁴ arereplaced by the group -(L₁)_(n)-.

In the compounds of formula (I), the groups represented by formulae (a)and (b) are bonded to each other via -(L₁)_(n)- at one of X⁵ to X⁸ andone of Y¹ to Y⁴ (the dotted lines are bonding sites):

Specific examples of the bonding manner between formulae (a) and (b) via-(L₁)_(n)- are represented by X⁶-(L₁)_(n)-Y³, X⁶-(L₁)_(n)-Y²,X⁶-(L₁)_(n)-Y⁴, X⁶-(L₁)_(n)-Y¹, X⁷-(L₁)_(n)-Y³, X⁵-(L₁)_(n)-Y³,X⁸-(L₁)_(n)-Y³, X⁷-(L₁)_(n)-Y², X⁷-(L₁)_(n)-Y⁴, X⁷-(L₁)_(n)-Y¹,X⁵-(L₁)_(n)-Y², X⁸-(L₁)_(n)-Y², X₈-(L₁)_(n)-Y⁴, X⁸-(L1)_(n)-Y¹,X⁵-(L₁)_(n)-Y¹, and X⁵-(L₁)_(n)-Y⁴. Preferably, X⁵, X⁶, X⁷ or X⁸ arebonded via -(L₁)_(n)- to Y² or Y³ or Y⁴, or Y², Y³ or Y⁴ are bonded via-(L₁)_(n)- to X⁶ or X. More preferably, the bonding manner isX⁶-(L₁)_(n)-Y³, X⁶-(L1)_(n)-Y², X⁷-(L1)_(n)-Y³ or X⁷-(L1)_(n)-Y².

Preferably, group A is therefore selected from the group consisting ofthe following formulae:

More preferably, A is selected from the group consisting of thefollowing formulae:

wherein X¹ to X⁸, Y¹, to Y⁸, R¹⁷, L₁ and n are defined above and thedotted line is a bonding site.

Most preferred groups A are selected from the group consisting of thefollowing formulae:

wherein R¹⁷, L₁ and n are defined above and the dotted line is a bondingsite, and

R^(1A), R^(2A), R^(3A), R^(4A), R^(5A), R^(6A), R^(7A), R^(8A), R^(1B),R^(2B), R^(3B), R^(4B), R^(5B), R^(6B), R^(7B), R^(8B) are defined asR_(Y), i.e. in each occurrence independently H, a substituted orunsubstituted alkyl group having 1 to 30 carbon atoms, a substituted orunsubstituted cycloalkyl group having a ring formed of 3 to 20 carbonatoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbonatoms, a substituted or unsubstituted aralkyl group having 7 to 24carbon atoms, a silyl group having 3 to 20 carbon atoms, a substitutedor unsubstituted hydrocarbon group having ring structure formed of 6 to30 carbon atoms or a substituted or unsubstituted aromatic heterocyclicgroup having a ring structure formed of 5 to 30 atoms, or a substitutedor unsubstituted alkylthio group having 1 to 20 carbon atoms, or asubstituted or unsubstituted arylthio group having 6 to 30 carbon atoms,or a substituted or unsubstituted aryloxy group having 6 to 30 carbonatoms, a cyano group or a halogen atom;

provided that, among R^(1A) to R^(8A) and R^(1B) to R^(8B) any twoadjacent residues may be bonded each other to form ring structures.

Preferably, R^(1A), R^(2A), R^(3A), R^(4A), R^(5A), R^(6A), R^(7A),R^(8A), R^(1B), R^(2B), R^(3B), R^(4B), R^(5B), R^(6B), R^(7B), R^(8B)are in each occurrence independently H, a substituted or unsubstitutedalkyl group having 1 to 30 carbon atoms, a substituted or unsubstitutedaromatic hydrocarbon group having ring structure formed of 6 to 30carbon atoms or a substituted or unsubstituted heterocyclic group havinga ring structure formed of 5 to 30 atoms;

provided that, among R^(1A) to R^(8A) and R^(1B) to R^(8B) any twoadjacent residues may be bonded each other to form ring structures;

more preferably, R^(1A), R^(2A), R^(3A), R^(4A), R^(5A), R^(6A), R^(7A),R^(8A), R^(1B), R^(2B), R^(3B), R^(4B), R^(5B), R^(6B), R^(7B), R^(8B)are in each occurrence independently H, methyl group, ethyl group,n-propyl group, isopropyl group, n-butyl group, s-butyl group, isobutylgroup, t-butyl group, a substituted or unsubstituted aromatichydrocarbon group having ring structure formed of 6 to 18 carbon atoms,or a substituted or unsubstituted heterocyclic group having a ringstructure formed of 5 to 18 atoms; most preferably, R^(1A), R^(2A),R^(3A), R^(4A), R^(5A), R^(6A), R^(7A), R^(8A), R^(1B), R^(2B), R^(3B),R^(4B), R^(5B), R^(6B), R^(7B), R^(8B) are in each occurrenceindependently H, methyl, ethyl, n-propyl, isopropyl group, n-butylgroup, s-butyl group, isobutyl group, t-butyl group, substituted orunsubstituted biphenyl, substituted or unsubstituted phenyl, substitutedor unsubstituted carbazolyl, substituted or unsubstituted dibenzofuryl,substituted or unsubstituted dibenzothienyl, further most preferablyR^(1A), R^(2A), R^(3A), R^(4A), R^(5A), R^(6A), R^(7A), R^(8A), R^(1B),R^(2B), R^(3B), R^(4B), R^(5B), R^(6B), R^(7B), R^(8B) are in eachoccurrence H.

Especially most preferred groups A are selected from the groupconsisting of the following formulae:

wherein R¹⁷, L₁ and n are defined above and the dotted line is a bondingsite.

Particularly Preferred Compounds of Formula (I)

Particularly preferred compounds of formula (I) are the compounds offormulae (Ia-1a), (Ia-1b), (Ib′-1a), (Ib′-1b), (Ic-1a), (Ic-1b),(Id-1a), (Id-1b), (If-1a), (If-1b), (Ig-1a) and (Ig-1b), wherein

R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹ and R³⁰, X_(A), X_(B), L andm have been described above, and A is (II′aa-1), (II′ab-1), (II′ac-1) or(II′ad-1), preferably, A is (II′aa-1a), (II′ab-1a), (II′ac-1a) or(II′ad-1a), wherein R¹⁷, L₁, n and R^(1A), R^(2A), R^(3A), R^(4A),R^(5A), R^(6A), R^(7A), R^(8A), R^(1B), R^(2B), R^(3B), R^(4B), R^(5B),R^(6B), R^(7B), R^(8B) are described above.

Most preferred compounds are the following compounds:

Synthesis of the Compounds of Formula (I)

The basic structures in formulae (I*a), (I*b), (I*c) and (I*d) areprepared as follows:

Basic Structure of Formula (I*a)

One example for the preparation of the basic structure of formula (I*a)is shown below:

Reaction for example in N-methyl-2-pyrrolidone in the presence ofpotassium carbonate.

Basic Structure of Formula (I*c)

One example for the preparation of the basic structure of formula (I*c)is shown below:

Reaction for example in N-methyl-2-pyrrolidone in the presence ofpotassium carbonate.

Basic Structure of Formula (I*d)

One example for the preparation of the basic structure of formula (I*d)is shown below:

Reaction for example in N-methyl-2-pyrrolidone in the presence ofpotassium carbonate.

Basic Structure of Formula (I*b)

One example for the preparation of the basic structure of formula (I*b)is shown below:

Reaction for example in N-methyl-2-pyrrolidone in the presence ofpotassium carbonate.

Basic Structure of Formula (I*b)

One further example for the preparation of the basic structure offormula (I*b) is shown below: Step i)

Reaction for example in N-methyl-2-pyrrolidone in the presence ofpotassium carbonate.

Step ii)

Reaction for example in DMF in the presence of N-bromosuccinimide.

The functionalization of the basic structures A, B, C, D and E mentionedabove with -(L)_(m)-A is for example carried out by reaction of thebasic structures with

in the presence of a phosphine ligand (e.g.2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl and Pd(0) (e.g.tris(dibenzylideneacetone)dipalladium(0)).

Details of the reaction steps and process conditions are mentioned aboveand in the examples of the present application.

Compounds of Formula (I) in Organic Electronics Applications

It has been found that the compounds of the formula (I) are particularlysuitable for use in applications in which charge carrier conductivity isrequired, especially for use in organic electronics applications, forexample selected from switching elements such as organic transistors,e.g. organic FETs and organic TFTs, organic solar cells and organiclight-emitting diodes (OLEDs).

The term organic EL device (organic electroluminescence device) is usedinterchangeable with the term organic light-emitting diode (OLED) in thefollowing; i.e. both terms have the same meaning in the sense of thepresent application.

The present invention further relates to a material for an organic ELdevice comprising at least one compound of formula (I).

The organic transistor generally includes a semiconductor layer formedfrom an organic layer with charge transport capacity; a gate electrodeformed from a conductive layer; and an insulating layer introducedbetween the semiconductor layer and the conductive layer. A sourceelectrode and a drain electrode are mounted on this arrangement in orderthus to produce the transistor element. In addition, further layersknown to those skilled in the art may be present in the organictransistor. The layers with charge transport capacity may comprise thecompounds of formula (I).

The organic solar cell (photoelectric conversion element) generallycomprises an organic layer present between two plate-type electrodesarranged in parallel. The organic layer may be configured on a comb-typeelectrode. There is no particular restriction regarding the site of theorganic layer and there is no particular restriction regarding thematerial of the electrodes. When, however, plate-type electrodesarranged in parallel are used, at least one electrode is preferablyformed from a transparent electrode, for example an ITO electrode or afluorine-doped tin oxide electrode. The organic layer is formed from twosublayers, i.e. a layer with p-type semiconductor properties or holetransport capacity, and a layer formed with n-type semiconductorproperties or charge transport capacity. In addition, it is possible forfurther layers known to those skilled in the art to be present in theorganic solar cell. The layers with charge transport capacity maycomprise the compounds of formula (I).

The compounds of formula (I) being particularly suitable in OLEDs foruse as matrix material in a light-emitting layer and/or as charge and/orexciton blocker material, i.e. as electron/exciton blocker material oras hole/exciton blocker material, and/or charge transport material, i.e.hole transport material or electron transport material, preferably asmatrix material in a light-emitting layer, especially in combinationwith a phosphorescence emitter and/or as hole transport material,especially in combination with a fluorescence emitter.

In the case of use of the inventive compounds of formula (I) in OLEDs,OLEDs which have good efficiencies and a long lifetime and which can beoperated especially at a low use and operating voltage are obtained. Theinventive compounds of formula (I) are suitable especially for use asmatrix and/or charge transport, i.e. hole or electron transport, and/orcharge blocker material, i.e. hole or electron blocker material.Furthermore, the compounds of the formula (I) can be used asconductor/complementary materials in organic electronics applicationsselected from switching elements and organic solar cells. (In the senseof the present application, the terms matrix and host are usedinterchangeable).

Organic EL Device (OLED)

The organic EL device as one embodiment of the invention comprises oneor more organic thin film layers including an emitting layer between acathode and an anode, and at least one layer of the organic thin filmlayers comprises the compound of formula (I).

As examples of the organic thin film layers that comprise the compoundof formula (I), an anode-side organic thin film layer (hole-transportinglayer, hole-injecting layer, or the like), an emitting layer, acathode-side organic thin film layer (electron-transporting layer,electron-injecting layer, or the like) provided between a cathode and anemitting layer, a spacing layer, a barrier layer or the like can begiven. The examples are not limited thereto.

The compound of formula (I) may be contained in any of theabovementioned layers, and can be used as a host material or a dopantmaterial in the emitting layer of a fluorescent emitting unit, a hostmaterial in the emitting layer of a phosphorescent emitting unit, ahole-transporting layer, an electron-transporting layer or the like ofan emitting unit.

Preferably, the compounds of the formula (I) are used as matrixmaterials (host materials), preferably in an emission layer of an OLED,more preferably in an emission layer of an OLED comprising at least onecompound of the formula (I) and at least one emitter material, whereinthe emitter material is preferably a fluorescent or phosphorescentemitter material, more preferably a green or red fluorescent orphosphorescent emitter material.

The organic EL device of the invention may be a fluorescent orphosphorescent monochromatic emitting device or may be afluorescent/phosphorescent hybrid white emitting device. It may be asimple emitting device having a single emitting unit or a tandememitting device having plural emitting units. Among them, the organic ELdevice may preferably be a phosphorescent emitting device.

As the representative device structure of a simple type organic ELdevice, the following device configuration can be given.

(1) Anode/Emitting Unit/Cathode

The emitting unit mentioned above may be a stacked type emitting unitcomprising plural phosphorescent emitting layers or plural fluorescentemitting layers. In this case, in order to prevent diffusion of excitonsgenerated in the phosphorescent emitting layer to the fluorescentemitting layer, a spacing layer may be provided between the emittinglayers. The representative layer configuration of the emitting unit isgiven below.

(a) Hole-transporting layer/Emitting layer (/Electron-transportinglayer)

(b) Hole-transporting layer/First phosphorescent emitting layer/Secondphosphorescent emitting layer (/Electron-transporting layer)

(c) Hole-transporting layer/Phosphorescent emitting layer/Spacinglayer/Fluorescent emitting layer (/Electron-transporting layer)

(d) Hole-transporting layer/First phosphorescent emitting layer/Secondphosphorescent emitting layer/Spacing layer/Fluorescent emitting layer(/Electron-transporting layer)

(e) Hole-transporting layer/First phosphorescent emitting layer/Spacinglayer/Second phosphorescent emitting layer/Spacing layer/Fluorescentemitting layer (/Electron-transporting layer)

(f) Hole-transporting layer/Phosphorescent emitting layer/Spacinglayer/First fluorescent emitting layer/Second fluorescent emitting layer(/Electron-transporting layer)

(g) Hole-transporting layer/Electron barrier layer/Emitting layer(/Electron-transporting layer)

(h) Hole-transporting layer/Emitting layer/Hole barrier layer(/Electron-transporting layer)

(i) Hole-transporting layer/Fluorescent emitting layer/Triplet barrierlayer (/Electron-transporting layer)

The phosphorescent or fluorescent emitting layer as mentioned above canemit different colors of light. Specifically, in the stacked emittinglayer (d), a layer configuration of the hole transporting layer/firstphosphorescent emitting layer (red emission)/second phosphorescentemitting layer (green emission)/spacing layer/fluorescent emitting layer(blue emission)/electron transporting layer or the like can be given.

Between each emitting layer and the hole-transporting layer or thespacing layer, an electron barrier layer may be provided appropriately.Between each emitting layer and the electron transporting layer, ahole-barrier layer may be provided appropriately. Due to provision of anelectron-barrier layer or a hole-barrier layer, electrons or holes canbe confined within the emitting layer, whereby possibility ofrecombination of carriers in the emitting layer can be increased, andthe life can be improved.

As the represented device configuration of a tandem organic EL device,the following device configuration can be given.

(2) Anode/First Emitting Unit/Intermediate Layer/Second EmittingUnit/Cathode

Here, as the first emitting unit and the second emitting unit, the sameemitting units as those mentioned above can independently be given, forexample.

In general, the intermediate layer is called an intermediate electrode,an intermediate conductive layer, a carrier-generating layer, anelectron-withdrawing layer, and a known material configuration thatsupplies electrons to the first emitting unit and supplies holes to thesecond emitting unit can be used.

FIG. 1 shows a schematic configuration of one example of the organic ELdevice of the invention. The organic EL device 1 comprises a substrate2, an anode 3, a cathode 4 and an emitting unit 10 provided between theanode 3 and the cathode 4. The emitting unit 10 comprises an emittinglayer 5 preferably comprising a host material and a dopant. A holeinjecting and transporting layer 6 or the like may be provided betweenthe emitting layer 5 and the anode 3 and an electron-injecting layer 8and an electron transporting layer 7 or the like (electron injecting andtransporting unit 11) may be provided between the emitting layer 5 andthe cathode 4. An electron-barrier layer may be provided on the anode 3side of the emitting layer 5 and a hole-barrier layer may be provided onthe cathode 4 side of the emitting layer 5.

Due to such configuration, electrons or holes can be confined in theemitting layer 5, whereby possibility of generation of excitons in theemitting layer 5 can be improved.

Herein, a host that is combined with a fluorescent dopant is referred toas a fluorescent host and a host that is combined with a phosphorescentdopant is referred to as a phosphorescent host. The fluorescent host andthe phosphorescent host are not distinguished only by the molecularstructure thereof. That is, the phosphorescent host means a materialconstituting a phosphorescent emitting layer that contains aphosphorescent dopant and does not mean a material that cannot be usedas a material constituting a fluorescent dopant. The same can be appliedto a fluorescent host.

Substrate

The organic EL device is usually formed on a transparent substrate. Thetransparent substrate is a substrate for supporting the organic ELdevice, and is preferably a flat and smooth substrate having a400-to-700-nm-visible-light transmittance of 50% or more. Specificexamples thereof include glass plates and polymer plates. Examples ofthe glass plate include those obtained by using as raw materialssoda-lime glass, barium/strontium-containing glass, lead glass,aluminosilicate glass, borosilicate glass, barium borosilicate glass,quartz, or the like. Examples of the polymer plate include thoseobtained by using as raw materials polycarbonate, acrylic polymer,polyethylene terephthalate, polyethersulfide, polysulfone, or the like.

Anode

The anode of the organic EL device plays a role for injecting holes intoits hole-transporting layer or emitting layer. It is effective to useone having a work function of 4.5 eV or more. As specific examples ofthe anode material, indium tin oxide alloy (ITO), tin oxide (N ESA),indium zinc oxide, gold, silver, platinum, copper, and the like can begiven. The anode can be formed by forming these electrode materials intoa thin film by vapor deposition, sputtering or the like. In the casewhere emission from the emitting layer is taken out through the anode,the transmittance of the anode to the emission is preferably more than10%. The sheet resistance of the anode is preferably several hundred Ω/□or less. The film thickness of the anode, which varies depending uponthe material thereof, is usually from 10 nm to 1 μm, preferably from 10to 200 nm.

Cathode

The cathode plays a role for injecting electrons into itselectron-injecting layer, electron-transporting layer or emitting layer.The cathode is preferably formed of a material having a small workfunction. The cathode material is not particularly restricted. Asspecific examples of the cathode material, indium, aluminum, magnesium,a magnesium-indium alloy, a magnesium-aluminum alloy, analuminum-lithium alloy, an aluminum-scandium-lithium alloy, amagnesium-silver alloy or the like can be given. As in the case of theanode, the cathode can be formed by forming the materials into a thinfilm by a deposition method, a sputtering method or the like. Ifnecessary, emission can be outcoupled from the cathode side.

Emitting Layer

The present invention relates—in one embodiment—to an organicelectroluminescence device, wherein the light emitting layer comprisesat least one compound of formula (I).

The emitting layer is an organic layer having an emitting function, andwhere a doping system is used, it usually comprises a host material anda dopant material.

The host material has a function of accelerating recombination ofelectrons and holes and confining excitons within the emitting layer.The dopant material has a function of emitting efficiently excitonsobtained by recombination.

In the case of a phosphorescent device, the host material has a functionof confining excitons mainly generated by a dopant within the emittinglayer.

Here, in the emitting layer, a double host (also referred to as ahost/cohost) that adjusts the carrier balance in the emitting layer maybe used by combining an electron-transporting host and ahole-transporting host or by other methods. It is preferred that theemitting layer comprise a first host material and a second host materialand that at least one component of the first host material and thesecond host material is the compounds of the formula (I) according tothe invention.

Double dopant may be used in which two or more types of dopant materialshaving a high quantum yield are incorporated, and each dopant emitslight. Specifically, by allowing a host, a red dopant and a green dopantto be co-deposited, yellow emission from the common emitting layer,whereby yellow emission is realized.

As for the emitting layer, by allowing plural emitting layers to be astacked body, electrons and holes are accumulated in the interface ofthe emitting layers, whereby the recombination region is concentrated inthe interface of the emitting layers. As a result, the quantumefficiency is improved.

Easiness in injection of holes to the emitting layer and easiness ininjection of electrons to the emitting layer may differ. Further, thehole-transporting performance and the electron transporting performanceindicated by the mobility of holes and electrons in the emitting layermay differ from each other.

The emitting layer can be formed by a known method such as a depositionmethod, a spin coating method, a LB method (Langmuir Blodgett method) orthe like, for example. The emitting layer can also be formed by forminga solution obtained by dissolving a binder such as a resin and materialcompounds in a solvent into a thin film by a spin coating method and thelike. The emitting layer is preferably a molecular deposited film. The“molecular deposited film” means a thin film formed by deposition of araw material compound in a vapor phase or a film formed bysolidification of a raw material compound in a solution state or aliquid phase state. Normally, this molecular deposited film differs froma thin film (molecular accumulated film) formed by a LB method inaggregation structure or high-order structure, or differ in functionderived from such difference in structure.

In a more preferred embodiment, the light-emitting layer is formed from0.1 to 70% by weight, preferably 1 to 30% by weight, of at least one ofthe emitter materials and 30 to 99.9% by weight, preferably 70 to 99% byweight, of at least one of the matrix materials mentioned in thespecification—in one embodiment at least one compound of the formula(I)—where the sum total of the emitter material and of the matrixmaterial adds up to 100% by weight.

(1) Phosphorescent Emitting Layer

The phosphorescent emitting layer usually comprises at least one emittermaterial and at least one host material. The phosphorescent host is acompound which confines the triplet energy of the phosphorescent dopantefficiently in the light emitting layer to cause the phosphorescentdopant to emit light efficiently.

A host material for phosphorescent emitting layer is usually selectedfrom known phosphorescent host materials. Specific examples of thepreferable phosphorescent host are, nitrogen-containing heteroaromatics,such as, indole derivatives, carbazole derivatives, pyridinederivatives, pyrimidine derivatives, triazine derivatives, quinolinederivatives, isoquinoline derivatives, quinazoline derivatives,nitrogenated-dibenzothiophene derivatives, nitrogenated-dibenzofuranderivatives, imidazole derivatives, such as benzimidazole derivatives,imidazopyridine derivatives, Benzimidazophenanthridine derivatives,benzimidzobenzimidazole derivatives; oxygen or sulfur containingheteroaromatics, such as thiophene derivatives, furan derivatives,benzothiophene derivatives, benzofuran derivatives, dibenzothiophenederivatives, dibenzofuran derivatives; aryl or heteroaryl substitutedamine derivatives; metal complexes; aromatic hydrocarbon derivatives,such as benzene derivatives naphthalene derivatives, phenanthrenederivatives, triphenylene derivatives, fluorene derivatives, and so on,preferably, nitrogen containing heteroaromatics, the most preferably,the compounds of the formula (I).

According to one embodiment, the light-emitting layer comprises at leastone emitter material and at least two matrix materials, wherein one ofthe matrix materials is a compound of the formula (I) and the othermatrix material(s) is/are used as co-host(s). Suitable other hostmaterials than the compounds of formula (I) (co-hosts) are mentionedbelow. However, it is also possible to use two or more differentcompounds of formula (I) as host material in the light-emitting layer inan OLED of the present application.

Said second host material is selected from general phosphorescent hostmaterials. Specific examples are selected from above mentionedderivatives, preferably, nitrogen containing heteroaromatics, morepreferably, following general formula (N-1). The present inventiontherefore further relates to an organic electroluminescence device,wherein the light emitting layer comprises a heterocyclic derivativerepresented by the general formula (N-1) and preferably at least onecompound of formula (I).

X^(n1), to X^(n3) each independently represents CR^(n4) or N,

R^(n1) to R^(n4) each independently represents hydrogen, halogen atom, asubstituted or unsubstituted alkyl group having 1 to 25 carbon atoms, asubstituted or unsubstituted alkenyl group having 2 to 25 carbon atoms,a substituted or unsubstituted alkynyl group having 2 to 25 carbonatoms, a substituted or unsubstituted cycloalkyl group having 3 to 25carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 25carbon atoms, a substituted or unsubstituted aryl group having 6 to 24carbon atoms, a substituted or unsubstituted heterocyclic group having 5to 30 cyclic atoms, a substituted or unsubstituted aryloxy group having6 to 24 carbon atoms, a substituted or unsubstituted alkylthio grouphaving 1 to 25 carbon atoms, a substituted or unsubsituted arylthiogroup having 6 to 24 carbon atoms, alkyl or aryl substituted silylgroup, alkyl or aryl substituted carbonyl group, or a substitutedphosphoryl group,

in the case of at least one of X^(n1) to X^(n3) represent CR^(n4), twoor more substituents selected among R^(n1)˜R^(n4) may be bonded to eachother to form a ring structure.

In one embodiment of the present invention, the compound of formula(N-1) is preferably represented by the formula (N-21).

Wherein,

each of X^(n1) to X^(n3), R^(n5) and R^(n6) is as defined in formula(N-1),

L^(n1) represents a substituted or unsubstituted aryl group having 6 to24 carbon atoms, or a substituted or unsubstituted heterocyclic grouphaving 5 to 30 cyclic atoms,

nf is 0, 1, 2, 3 or 4, when f is 2, 3 or 4, the plural L^(n1)s may besame or different each other,

Y^(n1) is carbon atom or nitrogen atom,

Ar^(n1) represents a substituted or unsubstituted aryl group having 6 to24 carbon atoms which shares a carbon atom of an adjacentnitrogen-containing 5-membered ring and Y1¹¹ and is fused to thenitrogen-containing 5-membered ring, or a substituted or unsubstitutedheterocyclic group having 5 to 30 cyclic atoms which shares a carbonatom of an adjacent nitrogen-containing 5-membered ring and Y1¹¹ and isfused to the nitrogen-containing 5-membered ring,

R^(n50) and R^(n51) each independently represents hydrogen, halogenatom, a substituted or unsubstituted alkyl group having 1 to 25 carbonatoms, a substituted or unsubstituted alkenyl group having 2 to 25carbon atoms, a substituted or unsubstituted alkynyl group having 2 to25 carbon atoms, a substituted or unsubstituted cycloalkyl group having3 to 25 carbon atoms, a substituted or unsubstituted alkoxy group having1 to 25 carbon atoms, a substituted or unsubstituted aryl group having 6to 24 carbon atoms, a substituted or unsubstituted heterocyclic grouphaving 5 to 30 cyclic atoms, a substituted or unsubstituted aryloxygroup having 6 to 24 carbon atoms, a substituted or unsubstitutedalkylthio group having 1 to 25 carbon atoms, a substituted orunsubsituted arylthio group having 6 to 24 carbon atoms, alkyl or arylsubstituted silyl group, alkyl or aryl substituted carbonyl group, asubstituted phosphoryl group or a cyano group, or R⁵⁰ and R⁵¹ may bebonded to each other to form a substituted or unsubstituted aryl grouphaving 6 to 24 carbon atoms.

The compound represented by formula (N-21) is preferably represented byformula (N-22).

Wherein

X^(n1) to X^(n3), R^(n5), R^(n6), L^(n1), nf, Y^(n1) and Ar^(n1) are asdefined in formula (N-21),

R^(n52) represents hydrogen, halogen atom, a substituted orunsubstituted alkyl group having 1 to 25 carbon atoms, a substituted orunsubstituted alkenyl group having 2 to 25 carbon atoms, a substitutedor unsubstituted alkynyl group having 2 to 25 carbon atoms, asubstituted or unsubstituted cycloalkyl group having 3 to 25 carbonatoms, a substituted or unsubstituted alkoxy group having 1 to 25 carbonatoms, a substituted or unsubstituted aryl group having 6 to 24 carbonatoms, a substituted or unsubstituted heterocyclic group having 5 to 30cyclic atoms, a substituted or unsubstituted aryloxy group having 6 to24 carbon atoms, a substituted or unsubstituted alkylthio group having 1to 25 carbon atoms, a substituted or unsubsituted arylthio group having6 to 24 carbon atoms, alkyl or aryl substituted silyl group, alkyl oraryl substituted carbonyl group, a substituted phosphoryl group or acyano group,

nc is 0, 1, 2, 3 or 4, when c is 2, 3 or 4, the plural R^(n52)s may besame or different each other and adjacent R^(n52)s may be bonded to eachother to form a ring structure.

The compound represented by formula (N-22) is preferably represented byformula (N-23).

Wherein X^(n1), to X^(n3), R^(n5), R^(n6), L^(n1), nf, R^(n52) and ncare as defined in formula (N-22).

The compound represented by formula (N-23) is preferably represented byformula (N-24).

Wherein X^(n1) to X^(n3), R^(n5), R^(n6), L^(n1), nf, R^(n52) and nc areas defined in formula (N-23),

nd is 0, 1, 2 or 3, when nd is 2 or 3, the plural R^(n52) are same ordifferent each other,

R^(n53) represents a substituted or unsubstituted alkyl group having 1to 25 carbon atoms, a substituted or unsubstituted cycloalkyl grouphaving 3 to 25 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 24 carbon atoms or a substituted or unsubstitutedheterocyclic group having 5 to 30 cyclic atoms.

In another embodiment, the compound represented by formula (N-22) ispreferably represented by formula (N-25).

Wherein X^(n1) to X^(n3), R^(n5), R^(n6), L^(n1), nf, R^(n52) and nc areas defined in formula (N-22),

Y^(n2) represents CR^(n54)R^(n55), NR^(n55), oxygen atom or sulfur atom,

R^(n54), R^(n55) and R^(n56) each independently represents a substitutedor unsubstituted alkyl group having 1 to 25 carbon atoms, a substitutedor unsubstituted cycloalkyl group having 3 to 25 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 24 carbon atoms or asubstituted or unsubstituted heterocyclic group having 5 to 30 cyclicatoms,

Ar^(n2) represents a substituted or unsubstituted aryl group having 6 to24 carbon atoms which shares carbon atoms of two adjacentnitrogen-containing 5-membered rings and is fused to the twonitrogen-containing 5-membered rings, or a substituted or unsubstitutedheterocyclic group having 5 to 30 cyclic atoms which shares carbon atomsof two adjacent nitrogen-containing 5-membered rings and is fused to thetwo nitrogen-containing 5-membered rings.

Y^(n2) in formula (N-25) preferably represents CR^(n54)R^(n55) orNR^(n56) (R^(n54) to R^(n56) are as defined in formula (N-25)).

The compound represented by formula (N-25) is preferably represented byany one of the following formulae (N-26A) to (N-26F).

Wherein X^(n1) to X^(n3), R^(n5), R^(n6), L^(n1), nf, R^(n52) and nc areas defined in formula (N-25), R^(n57) represents a substituted orunsubstituted alkyl group having 1 to 25 carbon atoms, a substituted orunsubstituted cycloalkyl group having 3 to 25 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 24 carbon atoms or asubstituted or unsubstituted heterocyclic group having 5 to 30 cyclicatoms,

e is 0, 1 or 2, when e is 2, the plural R^(n52)s may be same ordifferent each other.

The compound represented by formula (N-25) is more preferablyrepresented by any one of the following formulae (N-27A) to (N-27F).

Wherein X^(n1) to X^(n3), R^(n5), R^(n6), L^(n1), nf, R^(n52) and nc areas defined in formula (N-25), R^(n58) represents a substituted orunsubstituted alkyl group having 1 to 25 carbon atoms, a substituted orunsubstituted cycloalkyl group having 3 to 25 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 24 carbon atoms or asubstituted or unsubstituted heterocyclic group having 5 to 30 cyclicatoms,

ne is 0, 1 or 2, when ne is 2, the plural R^(n52)s may be same ordifferent each other.

In another embodiment, the compound represented by formula (N-22) can berepresented by formula (N-28).

Wherein X^(n1), to X^(n3), R^(n5), R^(n8), L^(n1), nf, R^(n52) and ncare as defined in formula (N-22).

In another embodiment, the compound represented by formula (N-1) ispreferably represented by formula (N-30).

Wherein X^(n1) to X^(n3), R^(n5) and R^(n6) are as defined in formula(N-1),

L1 represents a substituted or unsubstituted arylene group having 6 to24 carbon atoms or a substituted or unsubstituted heteroarylene grouphaving 5 to 30 cyclic atoms,

nf is 0, 1, 2, 3 or 4, when nf is 2, 3 or 4, the plural L^(n1)s may besame or different each other,

R^(n60) represents a substituted or unsubstituted fused-aryl grouphaving 10 to 24 carbon atoms or a substituted or unsubstitutedfused-heteroaryl group having 9 to 30 cyclic atoms.

Said substituted or unsubstituted fused-aryl group having 10 to 24carbon atoms of R^(n60) is preferably a mono-valent residue of thecompound represented by formula (a1-1) or (a1-2).

Wherein R^(n21) to R^(n36) each independently represents hydrogen atomor substituent R^(b), when plural R^(b)s exist, the plural R^(b)s may besame or different each other, and the plural R^(b)s may be bonded toeach other to form a ring structure,

R^(b) represents hydrogen, a substituted or unsubstituted alkyl grouphaving 1 to 25 carbon atoms, a substituted or unsubstituted alkenylgroup having 2 to 25 carbon atoms, a substituted or unsubstitutedalkynyl group having 2 to 25 carbon atoms, a substituted orunsubstituted cycloalkyl group having 3 to 25 carbon atoms, asubstituted or unsubstituted alkoxy group having 1 to 25 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 24 carbon atoms, asubstituted or unsubstituted heterocyclic group having 5 to 30 cyclicatoms, a substituted or unsubstituted aryloxy group having 6 to 24carbon atoms, a substituted or unsubstituted alkylthio group having 1 to25 carbon atoms, a substituted or unsubsituted arylthio group having 6to 24 carbon atoms, alkyl or aryl substituted silyl group, alkyl or arylsubstituted carbonyl group, a substituted phosphoryl group or a cyanogroup.

Preferable examples of the compound represented by formula (a1-1) are asfollows.

Among the above examples, a fused-aryl ring containing 4 or more rings,such as triphenylenyl group, is preferable.

Preferable examples of the compound represented by formula (a1-2) are asfollows.

Among the above examples, a fused-aryl ring containing 4 or more rings,such as fluoranthenyl group is preferable.

As the fused-heteroaryl group having 9 to 30 cyclic atoms of R^(n60), afused-heteroaryl group having 9 to 30 cyclic atoms selected from theabove-mentioned heteroaryl groups can be used. The substituted orunsubstituted fused-heteroaryl group having 9 to 30 cyclic atoms ofR^(n60) is preferably a mono-valent residue of the compound representedby formula (a2).

Wherein X^(n51) to X^(n58) each independently represents CH, C(Rb) or N,

R^(b) represents a substituted or unsubstituted alkyl group having 1 to25 carbon atoms, a substituted or unsubstituted alkenyl group having 2to 25 carbon atoms, a substituted or unsubstituted alkynyl group having2 to 25 carbon atoms, a substituted or unsubstituted cycloalkyl grouphaving 3 to 25 carbon atoms, a substituted or unsubstituted alkoxy grouphaving 1 to 25 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 24 carbon atoms, a substituted or unsubstituted heterocyclicgroup having 5 to 30 cyclic atoms, a substituted or unsubstitutedaryloxy group having 6 to 24 carbon atoms, a substituted orunsubstituted alkylthio group having 1 to 25 carbon atoms, a substitutedor unsubsituted arylthio group having 6 to 24 carbon atoms, alkyl oraryl substituted silyl group, alkyl or aryl substituted carbonyl group,a substituted phosphoryl group or a cyano group,

when plural R^(b)s exist, the plural R^(b)s may be same or differenteach other, and the plural R^(b)s may be bonded to each other to form aring structure,

Y^(n4) represents oxygen atom, sulfur atom, —NR^(d)— or—C(R^(e))(R^(f))—,

R^(d), R^(e) and R^(f) each independently represents hydrogen atom orsubstituent R^(b), when both of R^(e) and R^(f) are R^(b), the R^(b)smay be bonded to each other to form a ring structure.

The mono-valent residue of the compound represented by formula (a2) ispreferably mono-valent residue of the compound represented by formula(a2-1).

Wherein Y^(n4) is as defined in formula (a2),

R^(n71) to R^(n78) each independently represents hydrogen atom orsubstituent R^(b),

R^(b) is as defined in formula (a2),

when plural R^(b)s exist, the plural R^(b)s may be same or different andmay be bonded to each other to form a ring structure.

The compound represented by formula (N-30) is preferably represented byformula (N-31).

Wherein X^(n1) to X^(n3), R^(n5), R^(n6), L^(n1) and nf are as definedin formula (N-30),

R^(n59) represents a substituted or unsubstituted alkyl group having 1to 25 carbon atoms, a substituted or unsubstituted alkenyl group having2 to 25 carbon atoms, a substituted or unsubstituted alkynyl grouphaving 2 to 25 carbon atoms, a substituted or unsubstituted cycloalkylgroup having 3 to 25 carbon atoms, a substituted or unsubstituted alkoxygroup having 1 to 25 carbon atoms, a substituted or unsubstituted arylgroup having 6 to 24 carbon atoms, a substituted or unsubstitutedheterocyclic group having 5 to 30 cyclic atoms, a substituted orunsubstituted aryloxy group having 6 to 24 carbon atoms, a substitutedor unsubstituted alkylthio group having 1 to 25 carbon atoms, asubstituted or unsubsituted arylthio group having 6 to 24 carbon atoms,alkyl or aryl substituted silyl group, alkyl or aryl substitutedcarbonyl group, a substituted phosphoryl group or a cyano group,

nc is 0, 1, 2, 3 or 4, nd is 0, 1, 2 or 3,

when nc is 2, 3 or 4, and/or when nd is 2 or 3, the plural R^(n59)s maybe same or different, and the plural R^(n59)s may be bonded to eachother to form a ring structure.

In another embodiment, the compound represented by formula (N-30) ispreferably represented by formula (N-32).

Wherein X^(n1), to X^(n3), R^(n5), R^(n6), L^(n1) and nf are as definedin formula (N-30),

R^(n61) represents a substituted or unsubstituted fused-heteroaryl grouphaving 9 to 30 cyclic atoms and not containing nitrogen atom.

As the fused-heteroaryl group having 9 to 30 cyclic atoms and notcontaining nitrogen atom of R^(n61), a fused-heteroaryl group having 9to 30 cyclic atoms and not containing nitrogen atom selected from theabove-mentioned heteroaryl groups can be used.

The compound represented by formula (N-32) is preferably represented byformula (N-33).

Wherein X^(n1) to X^(n3), R^(n5), R^(n6), L^(n1) and nf are as definedin formula (N-32),

R^(n62) represents a substituted or unsubstituted alkyl group having 1to 25 carbon atoms, a substituted or unsubstituted alkenyl group having2 to 25 carbon atoms, a substituted or unsubstituted alkynyl grouphaving 2 to 25 carbon atoms, a substituted or unsubstituted cycloalkylgroup having 3 to 25 carbon atoms, a substituted or unsubstituted alkoxygroup having 1 to 25 carbon atoms, a substituted or unsubstituted arylgroup having 6 to 24 carbon atoms, a substituted or unsubstitutedheterocyclic group having 5 to 30 cyclic atoms, a substituted orunsubstituted aryloxy group having 6 to 24 carbon atoms, a substitutedor unsubstituted alkylthio group having 1 to 25 carbon atoms, asubstituted or unsubsituted arylthio group having 6 to 24 carbon atoms,alkyl or aryl substituted silyl group, alkyl or aryl substitutedcarbonyl group, a substituted phosphoryl group or a cyano group,

nc is 0, 1, 2, 3 or 4, when nc is 2, 3 or 4, the plural R^(n62)s may besame or different, and the plural R^(n62)s may be bonded to each otherto form a ring structure,

Y^(n3) represents an oxygen atom or a sulfur atom.

The present invention further relates to an organic electroluminescencedevice, wherein the light emitting layer comprises a heterocyclicderivative represented by the general formula (N-2) and at least onecompound of formula (I). The compound of formula (N-2) is in a preferredembodiment used as host material.

wherein,

L^(n1) represents a substituted or unsubstituted aryl group having 6 to24 carbon atoms, or a substituted or unsubstituted heterocyclic grouphaving 5 to 30 cyclic atoms,

nf is 0, 1, 2, 3 or 4, when f is 2, 3 or 4, the plural L^(n1)s may besame or different each other,

Y^(n1) is carbon atom or nitrogen atom,

Ar^(n1) represents a substituted or unsubstituted aryl group having 6 to24 carbon atoms which shares a carbon atom of an adjacentnitrogen-containing 5-membered ring and Y^(n1) and is fused to thenitrogen-containing 5-membered ring, or a substituted or unsubstitutedheterocyclic group having 5 to 30 cyclic atoms which shares a carbonatom of an adjacent nitrogen-containing 5-membered ring and Y^(n1) andis fused to the nitrogen-containing 5-membered ring,

R^(n50) and R^(n51) each independently represents hydrogen, halogenatom, a substituted or unsubstituted alkyl group having 1 to 25 carbonatoms, a substituted or unsubstituted alkenyl group having 2 to 25carbon atoms, a substituted or unsubstituted alkynyl group having 2 to25 carbon atoms, a substituted or unsubstituted cycloalkyl group having3 to 25 carbon atoms, a substituted or unsubstituted alkoxy group having1 to 25 carbon atoms, a substituted or unsubstituted aryl group having 6to 24 carbon atoms, a substituted or unsubstituted heterocyclic grouphaving 5 to 30 cyclic atoms, a substituted or unsubstituted aryloxygroup having 6 to 24 carbon atoms, a substituted or unsubstitutedalkylthio group having 1 to 25 carbon atoms, a substituted orunsubsituted arylthio group having 6 to 24 carbon atoms, alkyl or arylsubstituted silyl group, alkyl or aryl substituted carbonyl group, asubstituted phosphoryl group or a cyano group, or R⁵⁰ and R⁵¹ may bebonded to each other to form a substituted or unsubstituted aryl grouphaving 6 to 24 carbon atoms;

R^(n60) represents a substituted or unsubstituted fused-aryl grouphaving 10 to 24 carbon atoms or a substituted or unsubstitutedfused-heteroaryl group having 9 to 30 cyclic atoms.

Preferred groups R^(n60) are mentioned above.

The compound represented by formula (N-2) is preferably represented byformula (N-2-1).

wherein

R^(n60), L^(n1), nf, Y^(n1) and Ar^(n1) are as defined in formula (N-2),

R^(n52) represents hydrogen, halogen atom, a substituted orunsubstituted alkyl group having 1 to 25 carbon atoms, a substituted orunsubstituted alkenyl group having 2 to 25 carbon atoms, a substitutedor unsubstituted alkynyl group having 2 to 25 carbon atoms, asubstituted or unsubstituted cycloalkyl group having 3 to 25 carbonatoms, a substituted or unsubstituted alkoxy group having 1 to 25 carbonatoms, a substituted or unsubstituted aryl group having 6 to 24 carbonatoms, a substituted or unsubstituted heterocyclic group having 5 to 30cyclic atoms, a substituted or unsubstituted aryloxy group having 6 to24 carbon atoms, a substituted or unsubstituted alkylthio group having 1to 25 carbon atoms, a substituted or unsubsituted arylthio group having6 to 24 carbon atoms, alkyl or aryl substituted silyl group, alkyl oraryl substituted carbonyl group, a substituted phosphoryl group or acyano group,

nc is 0, 1, 2, 3 or 4, when c is 2, 3 or 4, the plural R^(n52)s may besame or different each other and adjacent R^(n52)s may be bonded to eachother to form a ring structure.

The compound represented by formula (N-2-1) is preferably represented byformula (N-2-2).

wherein R^(n60), L^(n1), nf, R^(n52) and nc are as defined in formula(N-2-1).

The compound represented by formula (N-2-2) is preferably represented byformula (N-2-3).

wherein R^(n60), L^(n1), nf, R^(n52) and nc are as defined in formula(N-2-2),

nd is 0, 1, 2 or 3, when nd is 2 or 3, the plural R^(n52) are same ordifferent each other,

R^(n53) represents a substituted or unsubstituted alkyl group having 1to 25 carbon atoms, a substituted or unsubstituted cycloalkyl grouphaving 3 to 25 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 24 carbon atoms or a substituted or unsubstitutedheterocyclic group having 5 to 30 cyclic atoms.

In another embodiment, the compound represented by formula (N-2-1) ispreferably represented by formula (N-2-4).

wherein R^(n69), L^(n1), nf, R^(n52) and nc are as defined in formula(N-2-1),

Y^(n2) represents CR^(n54)R^(n55), NR^(n55), oxygen atom or sulfur atom,

R^(n54), R^(n55) and R^(n56) each independently represents a substitutedor unsubstituted alkyl group having 1 to 25 carbon atoms, a substitutedor unsubstituted cycloalkyl group having 3 to 25 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 24 carbon atoms or asubstituted or unsubstituted heterocyclic group having 5 to 30 cyclicatoms,

Ar^(n2) represents a substituted or unsubstituted aryl group having 6 to24 carbon atoms which shares carbon atoms of two adjacentnitrogen-containing 5-membered rings and is fused to the twonitrogen-containing 5-membered rings, or a substituted or unsubstitutedheterocyclic group having 5 to 30 cyclic atoms which shares carbon atomsof two adjacent nitrogen-containing 5-membered rings and is fused to thetwo nitrogen-containing 5-membered rings.

Y^(n2) in formula (N-2-4) preferably represents CR^(n54)R^(n55) orNR^(n56) (R^(n54) to R^(n56) are as defined in formula (N-2-4)).

In another embodiment, the compound represented by formula (N-2-1) canbe represented by formula (N-2-7).

wherein R^(n69), X^(n1) to X^(n3), R^(n5), R^(n6), L^(n1), nf, R^(n52)and nc are as defined in formula (N-2-1).

Preferred groups R^(n60) are mentioned above.

Particularly preferred groups R^(n60) are mono-valent residuesrepresented by formula (a1-2).

wherein R^(n29) to R^(n36) each independently represents hydrogen atomor substituent R^(b),

when plural R^(b)s exist, the plural R^(b)s may be same or differenteach other, and the plural R^(b)s may be bonded to each other to form aring structure,

R^(b) represents hydrogen, a substituted or unsubstituted alkyl grouphaving 1 to 25 carbon atoms, a substituted or unsubstituted alkenylgroup having 2 to 25 carbon atoms, a substituted or unsubstitutedalkynyl group having 2 to 25 carbon atoms, a substituted orunsubstituted cycloalkyl group having 3 to 25 carbon atoms, asubstituted or unsubstituted alkoxy group having 1 to 25 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 24 carbon atoms, asubstituted or unsubstituted heterocyclic group having 5 to 30 cyclicatoms, a substituted or unsubstituted aryloxy group having 6 to 24carbon atoms, a substituted or unsubstituted alkylthio group having 1 to25 carbon atoms, a substituted or unsubsituted arylthio group having 6to 24 carbon atoms, alkyl or aryl substituted silyl group, alkyl or arylsubstituted carbonyl group, a substituted phosphoryl group or a cyanogroup.

Preferable examples of the compound represented by formula (a1-2) are asfollows.

Among the above examples, a fused-aryl ring containing 4 or more rings,such as fluoranthenyl group is preferable.

Examples for preferred compounds N-2 are therefore compounds of thefollowing formula:

According to another embodiment, the light-emitting layer comprises atleast one emitter material and at least two matrix materials, whereinone of the matrix materials is a material selected from before mentionedknown host materials and the other matrix material(s) is/are used asco-host(s). Suitable other host material(s) is/are selected from beforementioned general host materials.

In said embodiment, the light-emitting layer is formed from 0.1 to 70%by weight, preferably 1 to 30% by weight, of the at least one emittermaterial and 30 to 99.9% by weight, preferably 70 to 99% by weight, of afirst host and the further matrix material, where the sum total of theat least one emitter material, the further matrix materials adds up to100% by weight.

The content ratio of the compound of the first host material and thesecond matrix material as co-host in the light emitting layer is notparticularly limited and may be selected accordingly, and the ratio offirst host material: second host material is preferably 1:99 to 99:1,more preferably 10:90 to 90:10, each based on mass.

A phosphorescent dopant (phosphorescent emitting material) that formsthe emitting layer is a compound that can emit light from tripletexcited state. The phosphorescent dopant is not limited as long as itcan emit from triplet excited state. The phosphorescent dopant ispreferably an organic metal complex containing at least one metalselected from Ir, Pt, Os, Au, Cu, Re and Ru and a ligand. It ispreferred that the ligand have an ortho-metalated bond. In respect of ahigh phosphorescent quantum yield and capability of improving externalquantum yield of an emitting device, the phosphorescent dopant ispreferably a compound having a metal atom selected from Ir, Os and Pt.Further preferable are a metal complex such as an iridium complex, anosmium complex and a platinum complex, with an ortho-metalated complexbeing more preferable. Among them, an iridium complex and a platinumcomplex are more preferable, and an ortho-metalated iridium complex isparticularly preferable.

The phosphorescent host is a compound having a function of allowing aphosphorescent dopant to emit light efficiently by efficiently confiningthe triplet energy of the phosphorescent dopant in the emitting layer.The material for an organic EL device according to the invention ispreferable as the phosphorescent host. The emitting layer may compriseone kind of the material for an organic EL device according to theinvention or may comprise two or more kinds of the material for anorganic EL device according to the invention.

When the material for an organic EL device according to the invention isused as a host material of the emitting layer, the emission wavelengthof the phosphorescent dopant contained in the emitting layer is notparticularly restricted. It is preferred that at least one kind of thephosphorescent dopant materials contained in the emitting layer have apeak of an emission wavelength of 490 nm or more and 700 nm or less,more preferably 490 nm or more and 650 nm or less. As for the emissioncolor of the emitting layer, red, yellow and green are preferable, forexample. By using the compound according to the invention as the hostmaterial and by forming an emitting layer by doping the phosphorescentdopant having such an emission wavelength, it is possible to obtain along-lived organic EL device.

In the organic EL device according to the invention, other compoundsthan the material for an organic EL device according to the inventioncan appropriately be selected as the phosphorescent host according tothe above-mentioned purpose.

The material for an organic EL device according to the invention andother compounds may be used in combination as the phosphorescent hostmaterial in the same emitting layer. When plural emitting layers arepresent, as the phosphorescent host material for one of these emittinglayers, the material for an organic EL device according to the inventionis used, and as the phosphorescent host material for one of otheremitting layers, other compounds than the material for an organic ELdevice according to the invention may be used. The material for anorganic EL device according to the invention can be used in an organiclayer other than the emitting layer. In that case, as the phosphorescenthost of the emitting layer, other compounds than the material for anorganic EL device according to the invention may be used.

The content of the emitter materials (dopants), preferably thephosphorescent emitter materials, in the light emitting layer is notparticularly limited and selected according to the use of the device,and preferably 0.1 to 70% by mass, and more preferably 1 to 30% by mass.If being 0.1% by mass or more, the amount of light emission issufficient. If being 70% by mass or less, the concentration quenchingcan be avoided. The further component in the emitting layer is usuallyone or more host material, which is preferably present in an amount of30 to 99.9% by mass, more preferably 70 to 99% by mass, wherein the sumof the emitter material(s) and the host material(s) is 100% by mass.

Suitable metal complexes (dopants, especially phosphorescent dopants)for use in the inventive OLEDs, preferably as emitter material, aredescribed as following general formula (E-1).

Wherein M₁ is a metal having an atomic weight greater than 40,preferably, Ir, Pt, Pd, Rh, Re, Ru, Os, TI, Pb, Bi, In, Sn, Sb, Te, Au,or Ag, more preferably Ir, Pt, or Os, most preferably Ir, A₁ representsaryl group having 6 to 24 carbon atoms or heterocyclic group having 3 to24 cyclic atoms, preferably above mentioned substituents which may haveadditional substituents,

A2 represents nitrogen containing heterocyclic group having 3 to 24cyclic atoms, preferably above mentioned substituents which may haveadditional substituents,

Z₁ represents C or N, preferably N,

(X-Y) is an ancillary ligand, preferably acetylacetonate derivatives,picolinate derivatives, more preferably acetylacetonate derivatives,

m is a value from 1 to the maximum number of ligands that may beattached to the metal; and

m+n is the maximum number of ligands that may be attached to the metal.

If m or n is more than 2, two or more ligands may be the same ordifferent in each occurrence.

According to one embodiment, a metal complex represented by thefollowing general formula (E-2) is more preferable especially for greenand yellow emitter,

Wherein M₂ is a metal having an atomic weight greater than 40,preferably, Ir, Pt, Pd, Rh, Re, Ru, Os, TI, Pb, Bi, In, Sn, Sb, Te, Au,or Ag, more preferably Ir, Pt, or Os, most preferably Ir, A₃, A₅ eachindependently represents aryl group having 6 to 24 carbon atoms orheterocyclic group having 3 to 24 cyclic atoms, preferably abovementioned substituents which may have additional substituents,

A₄, A₆ each independently represents nitrogen containing heterocyclicgroup having 3 to 24 cyclic atoms, preferably above mentionedsubstituents which may have additional substituents,

Z₂, Z₃ each independently represents C or N, preferably N,

o is a value from 1 to the maximum number of ligands that may beattached to the metal; and o+p is the maximum number of ligands that maybe attached to the metal.

If o or p is more than 2, two or more ligands may be the same ordifferent in each occurrence.

A metal complex represented by the following general formula (T) or (β)is more preferable.

M represents the above mentioned metal atom,

B, C each independently represents aryl group having 6 to 24 carbonatoms or heteroaryl group having 3 to 24 cyclic atoms, preferably phenylgroup, dibenzofuran group, dibenzothiophene group, aza-dibenzofurangroup, aza-dibenzothiophene group, which may have additionalsubstituents,

A represents a nitrogen containing 6 membered ring structure which mayhave additional substituents, preferably pyridine, pyrimidine, morepreferably pyridine,

X⁴˜X⁸ each represents C or N, preferably C,

m represents oxidation state of the metal M, n is 1 or greater than 1,

L′ represents following chemical structure,

wherein A represents nitrogen containing 6 membered ring structure whichmay have additional substituents, preferably pyridine, pyrimidine, morepreferably pyridine,

B represents aryl group having 6 to 24 carbon atoms or heteroaryl grouphaving 3 to 24 cyclic atoms, preferably phenyl group, dibenzofurangroup, dibenzothiophene group, aza-dibenzofuran group,aza-dibenzothiophene group, which may have additional substituents,

X⁹ represents C or N, preferably, N.

Ra, Rb, Rc or Rd each independntly represents hydrogen, a substituted orunsubstituted alkyl group having 1 to 25 carbon atoms, a substituted orunsubstituted alkoxy group having 1 to 25 carbon atoms, a substituted orunsubstituted amino group, a substituted or unsubstituted alkenyl grouphaving 2 to 25 carbon atoms, a substituted or unsubstituted alkynylgroup having 2 to 25 carbon atoms, a substituted or unsubstitutedaralkyl group having 7 to 24 carbon atoms, a substituted orunsubstituted aryl group having 6 to 24 carbon atoms or a substituted orunsubstituted heterocyclic group having 5 to 30 cyclic atoms,

Wherein X represents NR, oxygen atom, sulfur atom, BR or Selenium atom,

R represents hydrogen atom, a substituted or unsubstituted alkyl grouphaving 1 to 25 carbon atoms,

A¹, to A⁸ independently represents CH, CR⁵ or N, preferably CH or CR⁵,

R¹ to R⁵ each independently represents a substituted or unsubstitutedalkyl group having 1 to 25 carbon atoms, a substituted or unsubstitutedaryl group having 6 to 24 ring carbon atoms,

n is 1, 2 or 3, preferably 1.

In another embodiment, a metal complex represented by any one of thefollowing general formula (V), (X), (Y), (Z) can be used.

Wherein R⁵⁰ to R⁵² each represents a substituted or unsubstituted alkylgroup having 1 to 25 carbon atoms, a substituted or unsubstituted arylgroup having 6 to 24 ring carbon atoms,

k is 0, 1, 2, 3 or 4, m is 0, 1 or 2, I is 0, 1, 2, 3 or 4,

M represents iridium atom (Ir), osmium atom (Os) or platinum atom (Pt).

Formula (V) is preferably represented by formula (V-1). Formula (X) ispreferably represented by formula (X-1) or (X-2).

Wherein R⁵⁰, M and k are as defined in formula (V) and (X).

(2) Fluorescent Emitting Layer

The fluorescent emitting layer usually comprises at least one emittermaterial and at least one host material.

A host material for fluorescent emitting layer is usually selected fromgeneral host materials, which preferably have wider band-gap than theemitter material to get highly efficient light emission from the emitterthrough energy transfer mechanism from the excited host to the emitter.Specific examples of the preferable fluorescent host are, substituted orunsubstituted above mentioned heterocyclic compound; or substituted orunsubstituted aromatic hydrocarbon compound, such as oligo-phenylenederivatives, naphthalene derivatives, fluorene derivatives, fluoranthenederivatives, anthracene derivatives, phenanthrene derivatives, pyrenederivatives, triphenylene derivatives, benzanthracene derivatives,chrysene derivatives, benzphenanthrene derivatives, naphthacenederivstives, benzochrysene derivatives, and so on, preferably anthracenederivatives, pyrene derivatives and naphthacene derivatives, morepreferably, anthracene derivatives represented by following generalformula (X) especially for fluorescent blue or green device.

Ar_(x1) and Ar_(x2) are independently a substituted or unsubstitutedaryl group including 6 to 50 ring carbon atoms, preferably phenyl group,biphenyl group, naphthyl group, phenanthryl group, fluorenyl group,fluoranthenyl group, anthryl group, pyrenyl group, benzphenanthrylgroup, triphenylenyl group, benzanthryl group, benzochrysenyl group, ora heterocyclic group including 5 to 50 ring atoms, preferably,benzofuranyl group, benzothiophenyl group, indolyl group,dibenzothiophenyl group, dibenzofuranyl group, carbazolyl group,benzocarbazoryl group, dibenzocarbazoryl group, indolophenanthryl group,naphthobenzofuranyl group, naphthobenzothiophenyl group,dinaphthofuranyl group, dinaphthothiophenyl group,benzophenanthlofuranyl group, benzophenanthlothiophenyl group,benzofurodibenzofuranyl group, benzothiodibenzothiophenyl group,benzofurodibenzotihiophenyl group, benzothiodibenzofuranyl group, morepreferably oxygen or sulfer containing heteroaromatics, such as furan orthiophene containing heteroaromatics in one of the part of theheteroaromatics. R_(x1) to R_(x8) are independently a hydrogen atom, asubstituted or unsubstituted aryl group including 6 to 50 ring carbonatoms, a substituted or unsubstituted heterocyclic group including 5 to50 ring atoms, an alkyl group including 1 to 50 carbon atoms, asubstituted or unsubstituted alkoxy group including 1 to 50 carbonatoms, a substituted or unsubstituted aralkyl group including 7 to 50carbon atoms, a substituted or unsubstituted aryloxy group including 6to 50 ring carbon atoms, a substituted or unsubstituted arylthio groupincluding 6 to 50 ring carbon atoms, a substituted or unsubstitutedalkoxycarbonyl group including 2 to 50 carbon atoms, a substituted orunsubstituted silyl group, a carboxy group, a halogen atom, a cyanogroup, a nitro group or a hydroxyl group.

An emitter material for fluorescent emitting layer is usually selectedfrom general emitter materials or fluorescent dyes, which preferablyhave high absorption co-efficiency and high quantum efficiency to gethighly efficient light emission from the emitter. Specific examples ofthe preferable fluorescent emitter are, aromatic hydrocarbonderivatives, such as oligo-phenylene derivatives, naphthalenederivatives, fluorene derivatives, fluoranthenyl group, fusedfluoranthenyl group, anthracene derivatives, phenanthrene derivatives,pyrene derivatives, triphenylene derivatives, benzanthracenederivatives, chrysene derivatives, benzphenanthrene derivatives,naphthacene derivstives, benzochrysene derivatives, and so on; aromaticor heterocyclic amine derivatives represented by following generalformula (Y); organic boron derivatives represented by general formula(Z),

Y is a substituted or unsubstituted aromatic hydrocarbon group including6 to 50 ring carbon atoms, preferably fused aromatic hydrocarbon group,or substituted or unsubstituted heterocyclic group having 5 to 50 cyclicatoms.

Ar_(y1), and Ar_(y2) are independently a substituted or unsubstitutedaryl group including 6 to 50 ring carbon atoms or a substituted orunsubstituted heterocyclic ring group including 5 to 50 ring atoms,preferably, oxygen or sulfur containing heterocyclic group.

Specific examples of Y include the above-mentioned fused aryl group. Yis preferably a substituted or unsubstituted anthryl group; asubstituted or unsubstituted pyrenyl group; a substituted orunsubstituted chrysenyl group; substituted or unsubstituted fluorenylgroup, especially substituted or unsubstituted mono-, di-, ortri-benzofuro-fused fluorene, or substituted or unsubstituted mono-,di-, or tri-benzothio-fused fluorene; substituted or unsubstituteddibenzofuran containing heterocyclic group; substituted or unsubstituteddibenzothiophene containing heterocyclic group.

n is an integer of 1 to 4. It is preferred that n be an integer of 1 to2.

Electron-Transporting Layer

The electron-transporting layer is an organic layer that is formedbetween the emitting layer and the cathode and has a function oftransporting electrons from the cathode to the emitting layer. When theelectron-transporting layer is formed of plural layers, an organic layerthat is nearer to the cathode is often defined as the electron-injectinglayer. The electron-injecting layer has a function of injectingelectrons from the cathode efficiently to the organic layer unit.

According to one embodiment, it is preferred that ET layer furthercomprising the other one or more layer(s) than electron injection layerto enhance efficiency and lifetime of the device, preferably between anelectron injection layer and an emitting layer as a hole blocking layer,a exciton blocking layer or a triplet blocking layer.

A compound of the formula (I) is also preferable as all the use of theelectron transporting layer, such as an electron transporting layer, anelectron-injecting layer, a hole blocking layer, a exciton blockinglayer or a triplet blocking layer.

According to one embodiment, it is preferred that an electron-donatingdopant be contained in the interfacial region between the cathode andthe emitting unit. Due to such a configuration, the organic EL devicecan have an increased luminance or a long life. Here, theelectron-donating dopant means one having a metal with a work functionof 3.8 eV or less. As specific examples thereof, at least one selectedfrom an alkali metal, an alkali metal complex, an alkali metal compound,an alkaline earth metal, an alkaline earth metal complex, an alkalineearth metal compound, a rare earth metal, a rare earth metal complex anda rare earth metal compound or the like can be mentioned.

As the alkali metal, Na (work function: 2.36 eV), K (work function: 2.28eV), Rb (work function: 2.16 eV), Cs (work function: 1.95 eV) and thelike can be given. One having a work function of 2.9 eV or less isparticularly preferable. Among them, K, Rb and Cs are preferable. Rb orCs is further preferable. Cs is most preferable. As the alkaline earthmetal, Ca (work function: 2.9 eV), Sr (work function: 2.0 eV to 2.5 eV),Ba (work function: 2.52 eV) and the like can be given. One having a workfunction of 2.9 eV or less is particularly preferable. As the rare-earthmetal, Sc, Y, Ce, Tb, Yb and the like can be given. One having a workfunction of 2.9 eV or less is particularly preferable.

Examples of the alkali metal compound include an alkali oxide such asLi₂O, Cs₂O, or K₂O, and an alkali halide such as LiF, NaF, CsF and KF.Among them, LiF, Li₂O and NaF are preferable. Examples of the alkalineearth metal compound include BaO, SrO, CaO, and mixtures thereof such asBa_(x)Sr_(1-x)O(0<x<1) and Ba_(x)Ca_(1-x)O (0<x<1). Among them, BaO, SrOand CaO are preferable. Examples of the rare earth metal compoundinclude YbF₃, ScF₃, ScO₃, Y₂O₃, Ce₂O₃, GdF₃ and TbF₃. Among these, YbF₃,ScF₃ and TbF₃ are preferable.

The alkali metal complexes, the alkaline earth metal complexes and therare earth metal complexes are not particularly limited as long as theycontain, as a metal ion, at least one of alkali metal ions, alkalineearth metal ions, and rare earth metal ions. Meanwhile, preferredexamples of the ligand include, but are not limited to, quinolinol,benzoquinolinol, acridinol, phenanthridinol, hydroxyphenyloxazole,hydroxyphenylthiazole, hydroxydiaryloxadiazole,hydroxydiarylthiadiazole, hydroxyphenylpyridine,hydroxyphenylbenzimidazole, hydroxybenzotriazole, hydroxyfluborane,bipyridyl, phenanthroline, phthalocyanine, porphyrin, cyclopentadiene,β-diketones, azomethines, and derivatives thereof.

Regarding the addition form of the electron-donating dopant, it ispreferred that the electron-donating dopant be formed in a shape of alayer or an island in the interfacial region. A preferred method for theformation is a method in which an organic compound (a light emittingmaterial or an electron-injecting material) for forming the interfacialregion is deposited simultaneously with deposition of theelectron-donating dopant by a resistant heating deposition method,thereby dispersing the electron-donating dopant in the organic compound.The dispersion concentration of the organic compound: theelectron-donating dopant (molar ratio) is 100:1 to 1:100, preferably 5:1to 1:5.

In a case where the electron-donating dopant is formed into the shape ofa layer, the light-emitting material or electron-injecting materialwhich serves as an organic layer in the interface is formed into theshape of a layer. After that, a reductive dopant is solely deposited bythe resistant heating deposition method to form a layer preferablyhaving a thickness of from 0.1 nm to 15 nm. In a case where theelectron-donating dopant is formed into the shape of an island, theemitting material or the electron-injecting material which serves as anorganic layer in the interface is formed into the shape of an island.After that, the electron-donating dopant is solely deposited by theresistant heating deposition method to form an island preferably havinga thickness of from 0.05 nm to 1 nm.

The ratio of the main component and the electron-donating dopant in theorganic EL device according to the invention is main component:electron-donating dopant=5:1 to 1:5 in terms of molar ratio, morepreferably 2:1 to 1:2.

As the electron-transporting material used in the electron-transportinglayer other than a compound of the formula (I), an aromatic heterocycliccompound having one or more hetero atoms in the molecule may preferablybe used. In particular, a nitrogen containing heterocyclic derivative ispreferable.

According to one embodiment, it is preferable that ET layer comprises anitrogen containing heterocyclics metal chelate, such as8-hydroxyquinolinolato aluminum, which is generally called as Alq₃.

According to the other embodiment, it is preferable that ET layercomprising substituted or unsubstituted nitrogen containing heterocyclicderivative.

Specific examples of the preferable heterocyclic derivative for ET layerare, 6-membered azine derivatives; such as pyridine derivatives,pyrimidine derivatives, triazine derivatives, pyrazine derivatives,preferably pyrimidine derivatives or triazine derivatives; 6-memberedfused azine derivatives, such as quinolone derivatives, isoquinolinederivatives, quinoxaline derivatives, quinazoline derivatives,phenanthroline derivatives, benzoquinoline derivatives,benzoisoquinoline derivatives, dibenzoquinoxaline derivatives,preferably quinolone derivatives, isoquinoline derivatives,phenanthroline derivatives; 5-membered heterocyclic derivatives, such asimidazole derivatives, oxazole derivatives, oxadiazole derivatives,triazole derivatives, thiazole derivatives, thiadiazole derivatives;fused imidazole derivatives, such as benzimidazole derivatives,imidazopyridine derivatives, naphthoimidazole derivatives,benzimidazophenanthridine derivatives, benzimidzobenzimidazolederivatives, preferably benzimidazole derivatives, imidazopyridinederivatives or benzimidazophenanthridine derivatives.

According to the other embodiment, it is preferable ET layer comprisesphosphine oxide derivative represented as Ar_(p1)Ar_(p2)Ar_(P3)P═O.

Ar_(p1)˜Ar_(p3) are the substituents of phosphor atom and eachindependently represent substituted or unsubstituted above mentionedaryl group or substituted or unsubstituted above mentioned heterocyclicgroup.

According to the other embodiment, it is preferable that ET layercomprises aromatic hydrocarbon derivatives.

Specific examples of the preferable aromatic hydrocarbon derivatives forET layer are, oligo-phenylene derivatives, naphthalene derivatives,fluorene derivatives, fluoranthenyl group, anthracene derivatives,phenanthrene derivatives, pyrene derivatives, triphenylene derivatives,benzanthracene derivatives, chrysene derivatives, benzphenanthrenederivatives, naphthacene derivstives, benzochrysene derivatives, and soon, preferably anthracene derivatives, pyrene derivatives andfluoranthene derivatives.

Hole-Transporting Layer

The hole-transporting layer is an organic layer that is formed betweenthe emitting layer and the anode, and has a function of transportingholes from the anode to the emitting layer. If the hole-transportinglayer is composed of plural layers, an organic layer that is nearer tothe anode may often be defined as the hole-injecting layer. Thehole-injecting layer has a function of injecting holes efficiently tothe organic layer unit from the anode.

A compound of the formula (I) is also preferable as all the use of thehole transporting layer, such as an hole transporting layer, anhole-injecting layer, a electron blocking layer.

Said hole injection layer is generally used for stabilizing holeinjection from anode to hole transporting layer which is generallyconsist of organic materials.

Organic material having good contact with anode or organic material withp-type doping is preferably used for the hole injection layer.

Acceptor materials, or fused aromatic hydrocarbon materials or fusedheterocycles which have high planarity, are preferably used, acceptormaterials are more preferably used for the hole injection layer.

Specific examples for acceptor materials other than a compound of theformula (I) are, the quinone derivatives with one or more electronwithdrawing groups, such asF₄TCNQ(2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane),1,2,3-Tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane,and so on; hexa-azatriphenylene derivatives with one or more electronwithdrawing groups, such as hexa-azatriphenylene-hexanitrile; aromatichydrocarbon derivatives with one or more electron withdrawing groups;aryl boron derivatives with one or more electron withdrawing groups, andso on.

p-doping is usually consist of one or more p-dopant materials and one ormore matrix materials. Matrix materials preferably have shallower HOMOlevel and p-dopant preferably have deeper LUMO level to enhance thecarrier density of the layer. Aryl or heteroaryl amine derivatives arepreferably used as the matrix materials. Specific examples for thematrix material are the same as that for hole transporting layer whichis explained at the later part. Specific examples for p-dopant otherthan a compound of the formula (I) are the above mentioned acceptormaterials, preferably the quinone derivatives with one or more electronwithdrawing groups, such as F₄TCNQ,1,2,3-Tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane.The ratio of the p-type dopant is preferably less than 20% of molarratio, more preferably less than 10%, such as 1%, 3%, 5% and so on.

Hole transporting layer is generally used for injecting and transportingholes efficiently, and aromatic or heterocyclic amine derivatives arepreferably used.

Specific examples for hole transporting layer other than a compound ofthe formula (I) are represented as general formula (H),

Ar₁˜Ar₃ each independently represents substituted or unsubstituted arylgroup having 5 to 50 carbon atoms or substituted or unsubstitutedheterocyclic group having 5 to 50 cyclic atoms, preferably phenyl group,biphenyl group, terphenyl group, naphthyl group, phenanthryl group,triphenylenyl group, fluorenyl group, spirobifluorenyl group,indenofluorenyl group, carbazolyl group, dibenzofuranyl group,dibenzothiophenyl group, carbazole substituted aryl group, dibenzofuransubstituted aryl group or dibenzothiophene substituted aryl group; twoor more substituents selected among Ar′˜Ar³ may be bonded to each otherto form a ring structure, such as carbazole ring structure, acridanering structure and so on.

According to one embodiment, it is preferable that at least one ofAr₁˜Ar₃ have additional one aryl or heterocyclic amine substituent, morepreferably Ar₁ has an additional aryl amino substituent, at the case ofthat it is preferable that Ar₁ represents substituted or unsubstitutedbiphenylene group, substituted or unsubstituted fluorenylene group.

A second hole transporting layer is preferably inserted between thefirst hole transporting layer and the emitting layer to enhance deviceperformance by blocking excess electrons or excitons. Specific examplesfor second hole transporting layer is the same as the first holetransporting layer. It is preferably that second hole transporting layerhave higher triplet energy to block triplet exciton especially forphosphorescent green device, such as the compounds of formula (I),bicarbazole derivatives, biphenylamine derivatives, triphenylenyl aminederivatives, fluorenyl amine detrivatives, carbazole substitutedarylamine derivatives, dibenzofuran substituted arylamine derivatives,dibenzothiophene substituted arylamine derivatives, and so on.

The present invention therefore further relates to the organicelectroluminescence device according to the present application, whereina hole transporting layer is provided between the anode and the lightemitting layer, and the hole transporting layer comprises at least onecompound of formula (I).

Spacing Layer

The spacing layer is a layer provided between the fluorescent emittinglayer and the phosphorescent emitting layer when the fluorescentemitting layer and the phosphorescent emitting layer are stacked inorder to prevent diffusion of excitons generated in the phosphorescentemitting layer to the fluorescent emitting layer or in order to adjustthe carrier balance. Further, the spacing layer can be provided betweenthe plural phosphorescent emitting layers.

Since the spacing layer is provided between the emitting layers, thematerial for the spacing layer is preferably a material having bothelectron-transporting properties and hole-transporting properties. Inorder to prevent diffusion of the triplet energy in adjacentphosphorescent emitting layers, it is preferred that the spacing layerhave a triplet energy of 2.6 eV or more. As the material used for thespacing layer, the same material as those used in the above-mentionedhole-transporting layer can be given.

Barrier Layer

It is preferred that the organic EL device according to the inventionhave a barrier layer such as an electron-barrier layer, a hole-barrierlayer and a triplet barrier layer in a part that is adjacent to theemitting layer. Here, the electron-barrier layer is a layer that servesto prevent leakage of electrons from the emitting layer to thehole-transporting layer, and the hole-barrier layer is a layer thatserves to prevent leakage of holes from the emitting layer to theelectron-transporting layer.

The triplet barrier layer prevents diffusion of triplet excitonsgenerated in the emitting layer to the surrounding layers, and has afunction of preventing energy deactivation of triplet excitons onmolecules in the electron-transporting layer other than the emittingdopant by confining the triplet excitons within the emitting layer.

When the triplet barrier layer is provided, in the phosphorescentemitting device, the following is considered. The triplet energy of thephosphorescent emitting dopant is taken as ET_(d) and the triplet energyof the compound used as the triplet barrier layer is taken as ET_(TB).If the energy relationship E^(T) _(d)<E^(T) _(TB) is satisfied, inrespect of energy, the triplet excitons of the phosphorescent emittingdopant is confined (i.e. the triplet excitons cannot be moved to othermolecules), whereby the energy deactivation route other than emission onthe dopant is cut off, leading to efficient emission. However, even whenthe relationship E^(T) _(d)<E^(T) _(TB) is established, if the energydifference ΔE^(T)=E^(T) _(TB)−ET_(d) is small, it is thought that, in anenvironment at around room temperature where the device is actuallydriven, due to thermal energy of the surrounding area, the tripletexcitons can move to other molecules by endothermically overcoming thisenergy difference ΔE^(T). In particular, in the case of phosphorescentemission that has a longer exciton life as compared with fluorescentemission, effects of the endothermic move of excitons relatively tend toappear. Relative to the thermal energy at room temperature, a largerenergy difference ΔE^(T) is preferable. The energy difference ΔE^(T) isfurther preferably 0.1 eV or more, and particularly preferably 0.2 eV ormore. On the other hand, in a fluorescent device, as the triplet barrierlayer of the TTF device configuration disclosed in WO2010/134350A1, theinventive compounds of formula (I) can be used.

The electron mobility of the material constituting the triplet barrierlayer is desirably 10⁻⁶ cm²/Vs or more in a field intensity range of0.04 to 0.5 MV/cm. As the method for measuring the electron mobility ofan organic material, several methods that include the Time of Flightmethod are known. Here, the electron mobility means an electron mobilitythat is determined by the impedance spectroscopy.

The electron mobility of the electron-injecting layer is desirably 10⁻⁶cm²/Vs or more in a field intensity range of 0.04 to 0.5 MV/cm. Thereason is that, by this electron mobility, injection of electrons fromthe cathode to the electron-transporting layer is promoted, and as aresult, injection of electrons to adjacent barrier layer and emittinglayer is promoted, enabling the device to be driven at a lower voltage.

The organic EL device using the inventive compounds of formula (I) canbe used as an emitting device in a panel module used in variousdisplays.

The organic EL device using the inventive compounds of formula (I) canbe used as a display element of a TV, a mobile phone and a PC; or anelectronic apparatus such as lightings or the like.

The OLEDs (organic EL devices) can be used in all apparatus in whichelectroluminescence is useful. Suitable devices are preferably selectedfrom stationary and mobile visual display units and illumination units.Stationary visual display units are, for example, visual display unitsof computers, televisions, visual display units in printers, kitchenappliances and advertising panels, illuminations and information panels.Mobile visual display units are, for example, visual display units incellphones, tablet PCs, laptops, digital cameras, MP3 players, vehiclesand destination displays on buses and trains. Further devices in whichthe inventive OLEDs can be used are, for example, keyboards; items ofclothing; furniture; wallpaper. In addition, the present inventionrelates to a device selected from the group consisting of stationaryvisual display units such as visual display units of computers,televisions, visual display units in printers, kitchen appliances andadvertising panels, illuminations, information panels, and mobile visualdisplay units such as visual display units in cellphones, tablet PCs,laptops, digital cameras, MP3 players, vehicles and destination displayson buses and trains; illumination units; keyboards; items of clothing;furniture; wallpaper, comprising at least one inventive organiclight-emitting diode or at least one inventive light-emitting layer.

The following examples are included for illustrative purposes only anddo not limit the scope of the claims. Unless otherwise stated, all partsand percentages are by weight.

EXAMPLES I Synthesis Examples Synthesis Example 1: Compound 1 SynthesisExample 1-1

In a nitrogen flushed 1000 ml three-necked round-bottomed flask4-bromo-2,5-difluoroaniline (20.5 g, 99 mmol) and 2-methoxyphenylboronicacid (17.97 g, 118 mmol) were dissolved in dimethoxyethane (200 ml)under nitrogen. 2M-sodium carbonate solution (99 ml, 197 mmol) andtetrakis(triphenylphosphine)palladium(0) (5.69 g, 4.93 mmol) were addedto the reaction mixture. The reaction mixture was heated in an oil bathat 100° C. for 7 hours. Water was added to the reaction mixture followedby extraction with toluene. The combined organic layers wereconcentrated. The crude product was added to a silica gel column and waseluted with dichloromethane and hexane to give 25 g of white solid(quant, Intermediate 1). The identification of the intermediate 1 wasmade by FD-MS (field desorption mass spectrometry) analysis.

Synthesis Example 1-2

In a 1000 ml three-necked round-bottomed flask intermediate 1 (19.4 g,82.4 mmol) was dissolved in acetone. 164 ml Hydrochloric acid (80 ml,494 mmol) was added to the reaction mixture dropwise. Sodium nitrite(6.8 g, 99 mmol), as a solution in water (16 ml), was added to thereaction mixture dropwise. Potassium iodide (20.5 g, 124 mmol), as asolution in water (80 ml), was added to the reaction mixture dropwise.Water was added to the reaction mixture followed by extraction withtoluene and then washed with 5% sodium sulfite solution. The combinedorganic layers were concentrated. The crude product was added to asilica gel column and was eluted with dichloromethane and hexane to give14.4 g of white solid (86% yield, intermediate 2). The identification ofthe intermediate 2 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 1-3

In a dried 200 ml three-necked round-bottomed flask intermediate 2 (8.9g, 25.7 mmol) and (5-chloro-2-methoxyphenyl)boronic acid (5.75 g, 30.9mmol) were dissolved in dimethoxyethane (52 ml).Tetrakis(triphenylphosphine)palladium(0) (0.594 g, 0.514 mmol) and2M-sodium carbonate solution (25.7 ml, 51.4 mmol), were added to thereaction mixture. The reaction mixture was heated in an oil bath at 100°C. for 7 hours. Water was added to the reaction mixture followed byextraction with toluene and then washed with water. The combined organiclayers were concentrated. The crude product was added to a silica gelcolumn and was eluted with toluene. The crude material was crystallizedfrom ethyl acetate to give 5.3 g of white solid (57% yield, intermediate3). The identification of the intermediate 3 was made by FD-MS (fielddesorption mass spectrometry) analysis.

Synthesis Example 1-4

In a nitrogen flushed 100 ml three-necked round-bottomed flaskintermediate 3 (4.70 g, 13.03 mmol) was dissolved in dichloromethaneunder nitrogen. The reaction mixture was cooled to 0° C. with anice/water bath. 1M-tribromoborane in dichloromethane (52.1 ml, 52.1mmol) was added to the reaction mixture dropwise. The reaction mixturewas heated to room temperature for 2 hours. The reaction mixture wascooled to 0° C. with an ice/water bath. Ice was added to the reactionmixture. The reaction mixture was filtered through a glass fiber paperand the filter cake was rinsed with water and dried to give 4.1 g ofwhite solid (95% yield, intermediate 4). The identification of theintermediate 4 was made by FD-MS (field desorption mass spectrometry)analysis.

Synthesis Example 1-5

In a dried 200 ml three-necked round-bottomed flask intermediate 4 (2.78g, 8.36 mmol) and potassium carbonate (3.46 g, 25.1 mmol) were dissolvedin N-methyl-2-pyrrolidone (84 ml) under nitrogen. The reaction mixturewas heated to 130° C. with an oil bath for 24 hours. The reactionmixture was added to water. The precipitation was rinsed with water andmethanol and dried to give 2.0 g of white solid (82% yield, intermediate5). The identification of the intermediate 5 was made by FD-MS (fielddesorption mass spectrometry) analysis.

Synthesis Example 1-6

The procedure of the synthesis of intermediate 1 was repeated except forusing 3-bromocarbazole in place of 4-bromo-2,5-difluoroaniline and using9-phenylcarbazole-3-yl boronic acid in place of 2-methoxyphenylboronicacid. The identification of the intermediate 6 was made by FD-MS (fielddesorption mass spectrometry) analysis.

Synthesis Example 1-7

In a nitrogen flushed 100 ml three-necked round-bottomed flaskintermediate 6 (2.04 g, 5 mmol), intermediate 5 (1.61 g, 5.5 mmol),2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (0.164 g, 0.4 mmol),tris(dibenzylideneacetone)dipalladium(0) (0.092 g, 0.1 mmol) and sodiumtert-butoxide (1.44 g, 15 mmol) were dissolved in xylene under nitrogen.The reaction mixture was heated 140° C. with an oil bath for 22 hours.The reaction mixture was filtered through a Buchner funnel and thefilter cake was dissolved in dichloromethan. The crude product was addedto a silica gel column and was eluted with dichloromethan and thenwashed with heated dioxane to give 1.88 g of white solid (57% yield,compound 1). The compound was measured for FD-MS (field desorption massspectrometry), maximum ultraviolet absorption wavelength (UV(PhMe) λmax)in toluene, and maximum fluorescence wavelength (FL(PhMe, λex=300 nm)λmax) in toluene.

The results are shown below.

FDMS: calcd. for C48H28N202=664, found m/z=664 (M+)

UV(PhMe) λmax: 341 nm

FL(PhMe, λex=300 nm) λmax: 401 nm

Synthesis Example 2: Compound 2 Synthesis Example 2-1

The procedure of the synthesis of intermediate 1 was repeated except forusing 1-bromo-2,4-dimethoxybenzene in place of4-bromo-2,5-difluoroaniline and using 2-fluorophenylboronic acid inplace of 2-methoxyphenylboronic acid. The identification of theintermediate 7 was made by FD-MS (field desorption mass spectrometry)analysis.

Synthesis Example 2-2

In a nitrogen flushed 300 ml three-necked round-bottomed flaskintermediate 7 (15.0 g, 64.5 mmol) was dissolved in DMF (30 ml) undernitrogen. The reaction mixture was cooled to 0° C. with an ice/waterbath. N-bromosuccinimide (11.2 g, 62.9 mmol), as a solution in DMF (30ml), was added to the reaction mixture dropwise. The reaction mixturewas heated to room temperature for 20 hours. Water was added to thereaction mixture followed by extraction with toluene. The combinedorganic layers were dried sodium sulfate, filtered and concentrated. Thecrude material was crystallized from acetone and methanol to give 14.8 gof white solid (73% yield). The identification of the intermediate 8 wasmade by FD-MS (field desorption mass spectrometry) analysis.

Synthesis Example 2-3

In a nitrogen flushed 500 ml three-necked round-bottomed flaskintermediate 8 (14.8 g, 47.6 mmol), bis(pinacolato)diboron (24.2 g, 95mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II)complex with dichloromethane (1.5 g, 3 mol %) and potassium acetate(14.0 g, 143 mmol) were dissolved in 1,4-dioxane (200 ml) undernitrogen. The reaction mixture was heated to 70° C. with an oil bath for20 hours. Toluene was added to the reaction mixture followed by vacumeconcentration. The crude product was added to a silica gel column andwas eluted with toluene to give 11.7 g of white solid (66% yield). Theidentification of the intermediate 9 was made by FD-MS (field desorptionmass spectrometry) analysis.

Synthesis Example 2-4

The procedure of the synthesis of intermediate 1 was repeated except forusing 4-bromo-1-fluoro-2-iodobenzene in place of4-bromo-2,5-difluoroaniline and using intermediate 10 in place of2-methoxyphenylboronic acid. The identification of the intermediate 11was made by FD-MS (field desorption mass spectrometry) analysis.

Synthesis Example 2-5

The procedure of the synthesis of intermediate 4 was repeated except forusing intermediate 11 in place of intermediate 3. The identification ofthe intermediate 12 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 2-6

The procedure of the synthesis of intermediate 5 was repeated except forusing intermediate 12 in place of intermediate 4. The identification ofthe intermediate 13 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 2-7

The procedure of the synthesis of compound 1 was repeated except forusing intermediate 13 in place of intermediate 5. The compound wasmeasured for FD-MS (field desorption mass spectrometry), maximumultraviolet absorption wavelength (UV(PhMe) λmax) in toluene, andmaximum fluorescence wavelength (FL(PhMe, λex=300 nm) λmax) in toluene.The results are shown below.

FDMS: calcd. for C48H28N202=664, found m/z=664 (M+)

UV(PhMe) λmax: 335 nm

FL(PhMe, λex=300 nm) λmax: 406 nm

Synthesis Example 3: Compound 3 Synthesis Example 3-1

The procedure of the synthesis of intermediate 1 was repeated except forusing 2,3-difluoro-1,4-diiodobenzene in place of4-bromo-2,5-difluoroaniline. The identification of the intermediate 14was made by FD-MS (field desorption mass spectrometry) analysis.

Synthesis Example 3-2

The procedure of the synthesis of intermediate 8 was repeated except forusing intermediate 7 in place of intermediate 8. The identification ofthe intermediate 15 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 3-3

The procedure of the synthesis of intermediate 1 was repeated except forusing intermediate 15 in place of 4-bromo-2,5-difluoroaniline. Theidentification of the intermediate 16 was made by FD-MS (fielddesorption mass spectrometry) analysis.

Synthesis Example 3-4

The procedure of the synthesis of intermediate 4 was repeated except forusing intermediate 16 in place of intermediate 3. The identification ofthe intermediate 17 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 3-5

The procedure of the synthesis of intermediate 5 was repeated except forusing intermediate 17 in place of intermediate 4. The identification ofthe intermediate 18 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 3-6

The procedure of the synthesis of compound 1 was repeated except forusing intermediate 18 in place of intermediate 5. The compound wasmeasured for FD-MS (field desorption mass spectrometry), maximumultraviolet absorption wavelength (UV(PhMe) λmax) in toluene, andmaximum fluorescence wavelength (FL(PhMe, λex=300 nm) λmax) in toluene.The results are shown below.

FDMS: calcd. for C48H28N202=664, found m/z=664 (M+)

UV(PhMe) λmax: 319 nm

FL(PhMe, λex=300 nm) λmax: 405 nm

Synthesis Example 4: Compound 4 Synthesis Example 4-1

In a nitrogen flushed 300 ml three-necked round-bottomed flask3-fluorodibenzofuran (5.49 g, 29.5 mmol) was dissolved intetrahydrofuran (58 ml) under nitrogen. The reaction mixture was cooledto −50° C. with a dry ice/acetone bath. n-Butyllithium solution 1.6 M inhexanes (18.4 ml, 29.5 mmol) was added to the reaction mixture.1,2-Dibromoethane (8.31 g, 44.2 mmol) was added to the reaction mixture.The reaction mixture was heated to room temperature for 5 hours. Waterand methanol were added to the reaction mixture followed by extractionwith toluene. The reaction mixture was washed with brine. The combinedorganic layers were dried MgSO₄, filtered and concentrated. The crudeproduct was added to a silica gel column and was eluted with hexane togive 7.1 g of white solid (86% yield). The identification of theintermediate 19 was made by FD-MS (field desorption mass spectrometry)analysis.

Synthesis Example 4-2

The procedure of the synthesis of intermediate 1 was repeated except forusing intermediate 19 in place of 4-bromo-2,5-difluoroaniline and using(2-chloro-5-methoxyphenyl)boronic acid in place of2-methoxyphenylboronic acid. The identification of the intermediate 20was made by FD-MS (field desorption mass spectrometry) analysis.

Synthesis Example 4-3

The procedure of the synthesis of intermediate 4 was repeated except forusing intermediate 20 in place of intermediate 3. The identification ofthe intermediate 21 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 4-4

The procedure of the synthesis of intermediate 5 was repeated except forusing intermediate 21 in place of intermediate 4. The identification ofthe intermediate 22 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 4-5

The procedure of the synthesis of compound 1 was repeated except forusing intermediate 22 in place of intermediate 5. The compound wasmeasured for FD-MS (field desorption mass spectrometry) and maximumfluorescence wavelength (FL(PhMe, λex=300 nm) λmax) in toluene. Theresults are shown below.

FDMS: calcd. for C48H28N202=664, found m/z=664 (M+)

FL(PhMe, λex=300 nm) λmax: 405 nm

Synthesis Example 5: Compound 5 Synthesis Example 5-1

The procedure of the synthesis of intermediate 1 was repeated except forusing intermediate 19 in place of 4-bromo-2,5-difluoroaniline. Theidentification of the intermediate 23 was made by FD-MS (fielddesorption mass spectrometry) analysis.

Synthesis Example 5-2

The procedure of the synthesis of intermediate 4 was repeated except forusing intermediate 23 in place of intermediate 3. The identification ofthe intermediate 24 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 5-3

The procedure of the synthesis of intermediate 5 was repeated except forusing intermediate 24 in place of intermediate 4. The identification ofthe intermediate 25 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 5-4

The procedure of the synthesis of intermediate 8 was repeated except forusing intermediate 25 in place of intermediate 7. The identification ofthe intermediate 26 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 5-5

The procedure of the synthesis of compound 1 was repeated except forusing intermediate 26 in place of intermediate 5. The compound wasmeasured for FD-MS (field desorption mass spectrometry) and maximumfluorescence wavelength (FL(PhMe, λex=300 nm) λmax) in toluene. Theresults are shown below.

FDMS: calcd. for C48H28N202=664, found m/z=664 (M+)

FL(PhMe, λex=300 nm) λmax: 403 nm

Synthesis Example 6: Compound 6 Synthesis Example 6-1

The procedure of the synthesis of intermediate 9 was repeated except forusing intermediate 5 in place of intermediate 8. The identification ofthe intermediate 27 was made by FD-MS (field desorption massspectrometry) analysis.

Synthesis Example 6-2

In a nitrogen flushed 350 ml three-necked round-bottomed flaskintermediate 6 (5.72 g, 14 mmol), 1-bromo-3-fluorobenzene (14.7 g, 84mmol), potassium phosphate tribasic (8.92 g, 42 mmol) inN-methyl-2-pyrrolidone(NMP) under nitrogen. The reaction mixture washeated 170° C. with an oil bath for 24 hours. The reaction mixture wascooled down and then precipitate salts were filtered. NMP was evaporatedfrom the crude product. Ethanol was added to the crude product, theproduct precipitated, the product was washed with ethanol and water anddried under vacuum at 80° C. The product crystallized in1-methoxy-2-proponol to give 5.02 of white solid (64% yield,intermediate 28). The identification of the intermediate 28 was made byFD-MS (field desorption mass spectrometry) analysis.

Synthesis Example 6-3

The procedure of the synthesis of intermediate 1 was repeated except forusing intermediate 28 in place of 4-bromo-2,5-difluoroaniline and usingintermediate 27 in place of 2-methoxyphenylboronic acid. The compoundwas measured for FD-MS (field desorption mass spectrometry) and maximumfluorescence wavelength (FL(PhMe, λex=350 nm) λmax) in toluene. Theresults are shown below.

FDMS: calcd. for C54H32N202=740, found m/z=740 (M+)

FL(PhMe, λex=350 nm) λmax: 405 nm

Synthesis Example 7: Compound 7 Synthesis Example 7-1

The procedure of the synthesis of intermediate 28 was repeated exceptfor using 1-bromo-4-fluorobenzene in place of 1-bromo-3-fluorobenzene.The identification of the intermediate 29 was made by FD-MS (fielddesorption mass spectrometry) analysis.

Synthesis Example 7-2

The procedure of the synthesis of intermediate 1 was repeated except forusing intermediate 29 in place of 4-bromo-2,5-difluoroaniline and usingintermediate 27 in place of 2-methoxyphenylboronic acid. The compoundwas measured for FD-MS (field desorption mass spectrometry) and maximumfluorescence wavelength (FL(PhMe, λex=350 nm) λmax) in toluene. Theresults are shown below.

FDMS: calcd. for C54H32N202=740, found m/z=740 (M+)

FL(PhMe, λex=350 nm) λmax: 406 nm

II Application Examples Application Example 1

A glass substrate with 120 nm-thick indium-tin-oxide (ITO) transparentelectrode (manufactured by Geomatec Co., Ltd.) used as an anode wasfirst cleaned with isopropanol in an ultrasonic bath for 10 min. Toeliminate any possible organic residues, the substrate was exposed to anultraviolet light and ozone for further 30 min. This treatment alsoimproves the hole injection properties of the ITO. The cleaned substratewas mounted on a substrate holder and loaded into a vacuum chamber.Thereafter, the organic materials specified below were applied by vapordeposition to the ITO substrate at a rate of approx. 0.2-1 Å/sec atabout 10⁻⁸-10⁻⁸ mbar. As a hole injection layer, 5 nm-thick of compoundHI was applied. Then 100 nm-thick of compound HT1 and 60 nm-thickcompound HT2 were applied as hole transporting layer 1 and holetransporting layer 2, respectively. Subsequently, a mixture of 5% byweight of an emitter compound(tris[2-phenylpyridinato-C²,N]iridium(III), 47.5% by weight of a host(compound 1) and 47.5% by weight of compound PH1 were applied to form a40 nm-thick phosphorescent-emitting layer. On the emitting layer, 30nm-thick compound ET was applied as an electron transport layer.Finally, 1 nm-thick LiF was deposited as an electron injection layer and80 nm-thick Al was then deposited as a cathode to complete the device.The device was sealed with a glass lid and a getter in an inert nitrogenatmosphere with less than 1 ppm of water and oxygen. To characterize theOLED, electroluminescence spectra were recorded at various currents andvoltages. In addition, the current-voltage characteristic was measuredin combination with the luminance to determine luminous efficiency andexternal quantum efficiency (EQE). Driving voltage (Voltage) is given ata current density of 10 mA/cm². The device results are shown in Table 1.

Application Example 2-4 and Comparative Application Example 1-3

Application Example 1 was repeated except for using each compound shownin Table 1 in place of the host (compound 1). The device results areshown in Table 1.

TABLE 1 Appl. Ex. Host Voltage [V] CIE (x, y) Appl. Ex. 1 Compound 1 4.80.31, 0.63 Appl. Ex. 2 Compound 2 4.9 0.31, 0.63 Appl. Ex. 3 Compound 34.9 0.31, 0.63 Appl. Ex. 4 Compound 4 4.8 0.31, 0.63 Comp. Appl. Ex. 1Comparative 5.2 0.31, 0.63 Compound 1 Comp. Appl. Ex. 2 Comparative 5.10.31, 0.63 Compound 2 Comp. Appl. Ex. 3 Comparative 5.7 0.31, 0.64Compound 3

The results shown in Table 1 demonstrate that the voltage is improved inthe case that an inventive compound 1, 2, 3 and 4 are used as greenhosts together with a co-host Compound PH1 in an OLED.

Application Example 5 and Comparative Application Example 4

Application Example 1 or Comparative Application Example 1 was repeatedexcept for using a host compound PH2 in place of the host (compoundPH1). The device results are shown in Table 2.

To characterize the OLED, electroluminescence spectra were recorded atvarious currents and voltages. In addition, the current-voltagecharacteristic was measured in combination with the luminance todetermine luminous efficiency and external quantum efficiency (EQE).Driving voltage (Voltage) is given at a current density of 10 mA/cm²,and 80% lifetime (LT80), the time spent until the initial luminance at50 mA/cm² is reduced to 80%, is recorded. The device results are shownin Table 2.

TABLE 2 Voltage LT80 Appl. Ex. Host [V] [hrs] CIE (x, y) Appl. Ex. 5Compound 1 4.7 150 0.31, 0.63 Comp. Appl. Ex. Comparative Compound 5.2 80 0.31, 0.63 4 1

The results shown in Table 2 demonstrate that the lifetime and voltageare improved in the case that an inventive compound 1 is used as a greenhost together with a co-host Compound PH2 in an OLED.

Application Examples 6, 7 and Comparative Application Example 5

Application Example 5 was repeated except for using each compound shownin Table 3 in place of the host shown in Table 2. The device results areshown in Table 3.

To characterize the OLED, electroluminescence spectra were recorded atvarious currents and voltages. In addition, the current-voltagecharacteristic was measured in combination with the luminance todetermine luminous efficiency and external quantum efficiency (EQE). 80%lifetime (LT80), the time spent until the initial luminance at 50 mA/cm²is reduced to 80%, is recorded. The device results are shown in Table 3.

TABLE 3 Appl. Ex. Host LT80 [hrs] CIE (x, y) Appl. Ex. 6 Compound 6 1400.31, 0.63 Appl. Ex. 7 Compound 7 150 0.31, 0.63 Comp. Appl. Ex. 5Comparative Compound 4 100 0.31, 0.63

The invention claimed is:
 1. A compound of formula (I):

wherein A is

X_(A) and X_(B) each independently represent O or S; r represents 1, 2or 3; in the case that r is 2 or 3, X_(B) as well as Ar₃ are the same ordifferent in each occurrence; Ar₁, Ar₂ and Ar₃ each independentlyrepresent a substituted or unsubstituted aromatic hydrocarbon grouphaving a ring structure formed of 6 to 30 carbon atoms or a substitutedor unsubstituted heterocyclic group having a ring structure formed of 5to 30 atoms, and which is linked to one aromatic hydrocarbon group ofAr₁, Ar₂ and Ar₃, respectively, via a carbon-carbon bond; L represents asingle bond, a substituted or unsubstituted alkylene group having 1 to30 carbon atoms, a substituted or unsubstituted cycloalkylene grouphaving a ring structure formed of 3 to 20 carbon atoms, a divalent silylgroup having 2 to 20 carbon atoms, a substituted or unsubstituteddivalent aromatic hydrocarbon group having a ring structure formed of 6to 30 carbon atoms or a substituted or unsubstituted divalentheterocyclic group having a ring structure formed of 5 to 30 atoms; m is1, 2 or 3; in the case that m is 2 or 3, L is the same or different ineach occurrence; R¹⁷ is a substituted or unsubstituted aromatichydrocarbon group having 6 to 30 ring carbon atoms or a substituted orunsubstituted heterocyclic group having 5 to 30 ring atoms, an alkylgroup having 1 to 30 carbon atoms, a substituted or unsubstitutedcycloalkyl group having a ring formed of 3 to 20 carbon atoms, asubstituted or unsubstituted aralkyl group having 7 to 24 carbon atoms;L₁ is a single bond, a substituted or unsubstituted alkylene grouphaving 1 to 30 carbon atoms, a substituted or unsubstitutedcycloalkylene group having a ring structure formed of 3 to 20 carbonatoms, a divalent silyl group having 2 to 20 carbon atoms, a substitutedor unsubstituted divalent aromatic hydrocarbon group having a ringstructure formed of 6 to 30 carbon atoms, or a substituted orunsubstituted divalent heterocyclic group having a ring structure formedof 5 to 30 atoms; n is 1, 2 or 3; in the case that n is 2 or 3, L₁ isthe same or different in each occurrence; Ar₄, Ar₅, Ar₆ and Ar₇ eachindependently represent a substituted or unsubstituted aromatichydrocarbon group having a ring structure formed of 6 to 30 carbonatoms, or a substituted or unsubstituted heterocyclic group having aring structure formed of 5 to 30 atoms; wherein the dotted line is abonding site.
 2. The compound according to claim 1, wherein r is
 1. 3.The compound according to claim 1, wherein m is
 1. 4. The compoundaccording to claim 1, wherein the compound of formula (I) has one of thefollowing formulae:

wherein X²¹ to X³⁰ each independently represent CR_(X) or N, R_(X) is ineach occurrence independently H, a substituted or unsubstituted alkylgroup having 1 to 30 carbon atoms, a substituted or unsubstitutedcycloalkyl group having a ring formed of 3 to 20 carbon atoms, asubstituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, asubstituted or unsubstituted aralkyl group having 7 to 24 carbon atoms,a silyl group having 3 to 20 carbon atoms, a substituted orunsubstituted aromatic hydrocarbon group having ring structure formed of6 to 30 carbon atoms or a substituted or unsubstituted heterocyclicgroup having a ring structure formed of 5 to 30 atoms, or a substitutedor unsubstituted alkylthio group having 1 to 20 carbon atoms, or asubstituted or unsubstituted arylthio group having 6 to 30 carbon atoms,or a substituted or unsubstituted aryloxy group having 6 to 30 carbonatoms, a cyano group or a halogen atom; wherein, among X²¹ to X³⁰, iftwo or more atoms are CR_(X), any two of CR_(X)s are optionally bondedeach other to form ring structures; wherein one of X²¹ to X³⁰ in eachformula (Ia), (Ib), (Ib′), (Ic), (Id), (Ie), (If), (Ig), (Ih), (Ii) and(Ij) represents a bonding site to (L)_(m)-A via a carbon atom.
 5. Thecompound according to claim 4, wherein X²¹ to X³⁰ each independentlyrepresent CR_(X).
 6. The compound according to claim 1, wherein A is agroup of the following formula:

X¹ to X⁸ and Y¹ to Y⁸ each independently represent CR_(Y) or N, R_(Y) isin each occurrence independently a substituted or unsubstituted alkylgroup having 1 to 30 carbon atoms, a substituted or unsubstitutedcycloalkyl group having a ring formed of 3 to 20 carbon atoms, asubstituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, asubstituted or unsubstituted aralkyl group having 7 to 24 carbon atoms,a silyl group having 3 to 20 carbon atoms, a substituted orunsubstituted hydrocarbon group having ring structure formed of 6 to 30carbon atoms or a substituted or unsubstituted aromatic heterocyclicgroup having a ring structure formed of 5 to 30 atoms, or a substitutedor unsubstituted alkylthio group having 1 to 20 carbon atoms, or asubstituted or unsubstituted arylthio group having 6 to 30 carbon atoms,or a substituted or unsubstituted aryloxy group having 6 to 30 carbonatoms, a cyano group or a halogen atom; wherein, among X¹ to X⁸ and Y¹to Y⁸, if two or more atoms are CR_(Y), any two of CR_(Y)s areoptionally bonded each other to form ring structures wherein one of X⁵,X⁶, X⁷ or X⁸ and one of Y¹, Y², Y³ or Y⁴, are bonded to each other viaL₁.
 7. The compound according to claim 1, wherein A is selected from thegroup consisting of the following formulae:


8. The compound according to claim 7, wherein A is selected from thegroup consisting of the following formulae:


9. The compound according to claim 1, wherein X¹, X², X³, X⁴, X⁵, X⁶,X⁷, X⁸, Y¹, Y², Y³, Y⁴, Y⁵, Y⁶, Y⁷ and Y⁸ is CR_(Y), wherein one ofR_(Y) at one of the positions X⁵ to X⁸ and one of R_(Y) at the positionsY¹ to Y⁴ are replaced by the group -(L₁)_(n)-.
 10. A material for anorganic electroluminescence device, comprising the compound according toclaim
 1. 11. An organic electroluminescence device, comprising: one ormore organic thin film layers comprising a light emitting layer betweena cathode and an anode, wherein at least one of the one or more organicthin film layers comprises the compound according to claim
 1. 12. Theorganic electroluminescence device according to claim 11, wherein thelight emitting layer comprises a phosphorescent material, which is anortho-metallated complex comprising a metal atom selected from the groupconsisting of iridium, osmium, and platinum.
 13. The organicelectroluminescence device according to claim 11, wherein a holetransporting layer is provided between the anode and the light emittinglayer, and the hole transporting layer comprises the compound.
 14. Theorganic electroluminescence device according to claim 11, wherein thelight emitting layer comprises the compound according to claim
 1. 15.The organic electroluminescence device according to claim 14, whereinthe light emitting layer further comprises a heterocyclic derivativerepresented by general formula (N-1):

wherein X^(n1) to X^(n3) each independently represents CR^(n4) or N,R^(n1) to R^(n4) each independently represents hydrogen, halogen atom, asubstituted or unsubstituted alkyl group having 1 to 25 carbon atoms, asubstituted or unsubstituted alkenyl group having 2 to 25 carbon atoms,a substituted or unsubstituted alkynyl group having 2 to 25 carbonatoms, a substituted or unsubstituted cycloalkyl group having 3 to 25carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 25carbon atoms, a substituted or unsubstituted aryl group having 6 to 24carbon atoms, a substituted or unsubstituted heterocyclic group having 5to 30 cyclic atoms, a substituted or unsubstituted aryloxy group having6 to 24 carbon atoms, a substituted or unsubstituted alkylthio grouphaving 1 to 25 carbon atoms, a substituted or unsubsituted arylthiogroup having 6 to 24 carbon atoms, alkyl or aryl substituted silylgroup, alkyl or aryl substituted carbonyl group, or a substitutedphosphoryl group, in the case of at least one of X^(n1) to X^(n3)represent CR^(n4), two or more substituents selected among R^(n1)˜R^(n4)are optionally bonded to each other to form a ring structure.